Impact of Right Atrial Remodeling in Heart Failure With Preserved Ejection Fraction

BackgroundFew studies have investigated right atrial (RA) remodeling in heart failure (HF) with preserved ejection fraction (HFpEF). This study sought to characterize the RA remodeling in HFpEF and to determine its prognostic significance.Methods and ResultsPatients with HFpEF were classified based on the presence of RA enlargement (RA volume index >39 mL/m² in men and >33 mL/m² in women). Compared with patients with normal RA size (n = 234), patients with RA dilation (n = 67) showed a higher prevalence of atrial fibrillation (AF), worse right ventricular systolic function, more severe pulmonary hypertension, and a greater prevalence of mild tricuspid regurgitation, as well as impaired RA reservoir function, with increased hepatobiliary enzyme levels. AF was strongly associated with the presence of RA dilation (odds ratio [OR] 10.2, 95% confidence interval [CI] 4.00–26.1 in current AF vs no AF and odds ratio 3.38, 95% CI 1.26–9.07, earlier AF vs no AF). Patients with RA dilation had more than a two-fold increased risk of composite outcomes of all-cause mortality or HF hospitalization (adjusted hazard ratio 2.01, 95% CI 1.09–3.70, P = .02). The presence of RA dilation also displayed an additive prognostic value over left atrial dilation alone.ConclusionsThese data demonstrate that HFpEF with RA remodeling is associated with distinct echocardiographic features characterizing advanced right heart dysfunction with an increased risk of adverse outcomes.     

The Impact of Catheter Ablation on the Dynamic Function of the Left Atrium in Patients with Atrial Fibrillation: Insights from Four‐Dimensional Computed Tomographic Images

Functional Evaluation of the LA by Dynamic CT. Introduction: Elucidating the functional properties and remodeling process of the entire left atrium (LA) is important not only for offering the mechanistic insight into atrial fibrillation (AF) but also for assessing the effectiveness of catheter ablation. Methods: We included 65 patients with paroxysmal AF and 29 controls. Baseline multidetector computed tomography (MDCT) was acquired in all subjects and a follow‐up MDCT was available in 48 patients after pulmonary vein and LA ablation. The 3‐dimensional images at atrial end‐diastole (ED) and end‐systole (ES) were analyzed. Results: The LA volume (ED: 61.11 ± 15.94 vs 54.12 ± 8.94 mL/m², P = 0.03; ES: 45.29 ± 17.64 vs 33.38 ± 7.78 mL/m², P < 0.001) was increased, and ejection fraction (EF) (26.93 ± 13.40 vs 38.09 ± 11.62%, P < 0.001) decreased in AF patients as compared to controls. After ablation, the ES LA volume (44.73 ± 14.93 vs 38.04 ± 11.51 mL/m², P = 0.04) decreased and the LA EF (25.04 ± 13.13 vs 30.82 ± 7.85%, P = 0.03) increased in patients without any AF recurrence. The wall motion (WM) analysis of the 18 segments of LA revealed increased motional magnitudes of entire LA except for the anterior roof. In contrast, the volume, EF, and WM of LA remained similar in patients with recurrence. Conclusion: Dilated LA with global hypokinesia was noted in AF patients. Improved LA transport function was demonstrated in patients without any recurrence after ablation. However, the anatomic and functional reverse remodeling was not significant in patients with AF recurrence. (J Cardiovasc Electrophysiol, Vol. 21, pp. 270–277, March 2010)     

Structural Cardiac Remodeling in Atrial Fibrillation

ObjectivesThis study sought to evaluate preablation computed tomography angiography (CTA) for atrial and epicardial features to predict atrial fibrillation (AF) recurrence after ablation.BackgroundStructural atrial remodeling is a process associated with occurrence or persistence of AF. Different anatomical imaging features have been proposed to influence atrial remodeling both negatively and positively as substrate for AF.MethodsPatients with nonvalvular AF underwent cardiac CTA before pulmonary vein isolation at 2 high-volume centers. Left atrial (LA) and right atrial volumes, LA wall thickness (LAWT), and epicardial adipose tissue volume and attenuation were evaluated. Additional subanalyses of electroanatomical maps were made. Follow-up was performed for at least 12 months, including subanalysis of repeated cardiac CTA studies. Interrater variability was assessed.ResultsOf 732 patients, 270 (36.9%) had AF recurrence after a mean of 7 months. CT analysis revealed larger indexed LA volume (47.3 mL/m² vs 43.6 mL/m²; P = 0.0001) and higher mean anterior (1.91 mm vs 1.65 mm; P < 0.0001) and posterior (1.61 mm vs 1.39 mm; P = 0.001) LAWT in patients with AF recurrence. Epicardial adipose tissue volume in patients with AF recurrence was higher (144.5 mm³ vs 128.5 mm³; P < 0.0001) and further progressed significantly in a subset of 85 patients after 2 years (+11.8 mm² vs −3.5 mm²; P = 0.041). Attenuation levels were lower, indicating a higher lipid component associated with AF recurrence (−69.1 HU vs −67.5 HU; P = 0.001). A total of 103 atrial voltage maps were highly predictive of AF recurrence and showed good discriminatory power for patients with low voltage >50% and LAWT (1.55 ± 0.5 mm vs 1.81 ± 0.6 mm; P = 0.032). Net reclassification improvement (NRI) showed a significant incremental benefit (NRI = 0.279; P < 0.0001) when adding LAWT to established risk models.ConclusionsAtrial wall thickness, epicardial fat volume, and attenuation are associated with AF recurrence in patients undergoing ablation therapy.     

Relationship between mean right atrial pressure and Doppler parameters in patients with right ventricular infarction

BACKGROUND: The incidence of an inferior left ventricular infarction involving the right ventricle is very high, ranging from 14 to 84%. Isolated right ventricular infarction accounts for < 3% of all cases of infarction. HYPOTHESIS: The aim of the present study was to assess the relationship between Doppler parameters of hepatic vein and tricuspid inflow, as well as mean right atrial (RA) pressure in patients with right ventricular infarction. METHODS: In all, 59 consecutive patients with inferior left ventricular infarction involving the right ventricle were selected for the study. All patients underwent Doppler echocardiographic evaluation of tricuspid and hepatic vein parameters and catheterization of the right side of the heart. Patients were divided into two groups according to the presence or absence of severe tricuspid regurgitation. RESULTS: In patients with severe tricuspid regurgitation, a significant correlation (r = 0.64; p < 0.001) between RA maximal volume and mean right atrial pressure (RAP) was found, and the sensitivity of RA maximal volume in identifying mean RAP > 7 mmHg was 64% with a specificity of 78%. In patients without severe tricuspid regurgitation, the most significant relationship was observed between mean RAP and inferior vena cava collapse index. Significant correlations between maximal and minimal diameters of the inferior vena cava were also observed. CONCLUSIONS: Echocardiographic and Doppler parameters may be useful for evaluating mean RAP in patients with right ventricular infarction. In patients with severe tricuspid regurgitation, the more important parameters are maximal and minimal RA volumes. In patients without severe tricuspid regurgitation together with right atrial volume, the important parameters are acceleration and deceleration time of the tricuspid inflow peak E velocity and hepatic systolic and diastolic venous flow.     

Impact of Atrial Fibrillation Ablation on Left Ventricular Filling Pressure and Left Atrial Remodeling

Background

Left ventricular (LV) diastolic dysfunction is associated with new-onset atrial fibrillation (AF), and the estimation of elevated LV filling pressures by E/e'' ratio is related to worse outcomes in patients with AF. However, it is unknown if restoring sinus rhythm reverses this process.

Objective

To evaluate the impact of AF ablation on estimated LV filling pressure.

Methods

A total of 141 patients underwent radiofrequency (RF) ablation to treat drug-refractory AF. Transthoracic echocardiography was performed 30 days before and 12 months after ablation. LV functional parameters, left atrial volume index (LAVind), and transmitral pulsed and mitral annulus tissue Doppler (e'' and E/e'') were assessed. Paroxysmal AF was present in 18 patients, persistent AF was present in 102 patients, and long-standing persistent AF in 21 patients. Follow-up included electrocardiographic examination and 24-h Holter monitoring at 3, 6, and 12 months after ablation.

Results

One hundred seventeen patients (82.9%) were free of AF during the follow-up (average, 18 ± 5 months). LAVind reduced in the successful group (30.2 mL/m² ± 10.6 mL/m² to 22.6 mL/m² ± 1.1 mL/m², p < 0.001) compared to the non-successful group (37.7 mL/m² ± 14.3 mL/m² to 37.5 mL/m² ± 14.5 mL/m², p = ns). Improvement of LV filling pressure assessed by a reduction in the E/e'' ratio was observed only after successful ablation (11.5 ± 4.5 vs. 7.1 ± 3.7, p < 0.001) but not in patients with recurrent AF (12.7 ± 4.4 vs. 12 ± 3.3, p = ns). The success rate was lower in the long-standing persistent AF patient group (57% vs. 87%, p = 0.001).

Conclusion

Successful AF ablation is associated with LA reverse remodeling and an improvement in LV filling pressure.     

Predictors of Severe Tricuspid Regurgitation in Patients with Permanent Pacemaker or Automatic Implantable Cardioverter-Defibrillator Leads

Patients with permanent pacemaker or automatic implantable cardioverter-defibrillator (AICD) leads have an increased prevalence of tricuspid regurgitation. However, the roles of cardiac rhythm and lead-placement duration in the development of severe tricuspid regurgitation are unclear.We reviewed echocardiographic data on 26 consecutive patients who had severe tricuspid regurgitation after permanent pacemaker or AICD placement; before treatment, they had no organic tricuspid valve disease, pulmonary hypertension, left ventricular dysfunction, or severe tricuspid regurgitation. We compared the results to those of 26 control subjects who had these same devices but no more than mild tricuspid regurgitation.The patients and control subjects were similar in age (mean, 81 ±6 vs 81 ±8 yr; P = 0.83), sex (male, 42% vs 46%; P = 0.78), and left ventricular ejection fraction (0.60 ±0.06 vs 0.58 ± 0.05; P = 0.4). The patients had a higher prevalence of atrial fibrillation (92% vs 65%; P=0.01) and longer median duration of pacemaker or AICD lead placement (49.5 vs 5 mo; P < 0.001). After adjusting for age, sex, and right ventricular systolic pressure by multivariate logistic regression analysis, we found that atrial fibrillation (odds ratio=6.4; P = 0.03) and duration of lead placement (odds ratio=1.5/yr; P = 0.001) were independently associated with severe tricuspid regurgitation.Out study shows that atrial fibrillation and longer durations of lead placement might increase the risk of severe tricuspid regurgitation in patients with permanent pacemakers or AICDs.Key words: Atrial fibrillation/complications, cardiac pacing, artificial/adverse effects, defibrillators, implantable/adverse effects, disease progression, echocardiography, electrodes, implanted/adverse effects, pacemaker, artificial/adverse effects, risk factors, tricuspid valve insufficiency/diagnosis/etiology, ventricular dysfunction, right/diagnosis/etiologyPatients with permanent pacemaker (PPM) or automatic implantable cardioverter-defibrillator (AICD) leads have an increased prevalence of significant tricuspid regurgitation (TR). Tricuspid regurgitation can be caused by various mechanisms, including pulmonary hypertension, direct lead interference with valve closure, tricuspid valve leaflet trauma from laceration and perforation, infective endocarditis, and fibrous adherence of pacemaker leads to the tricuspid valve apparatus.¹ Patients with long-standing atrial fibrillation (AF) can also develop severe TR even when their tricuspid valves are structurally normal.² In addition, patients with PPM leads have an increased prevalence of TR.³ Investigators in several large studies concluded that having a PPM or AICD increases the degree of TR in some patients.^1,3–5 However, it is unclear whether the chronic presence of device leads results in increased TR. We therefore sought to determine the predictors of severe TR in patients who have PPM or AICD leads. We hypothesized that a longer duration of PPM or AICD lead placement and the presence of AF were the chief risk factors.     

Pacemaker-Detected Atrial Fibrillation in Patients With Pacemakers: Prevalence,Predictors, and Current Use of Oral Anticoagulation

Background

Dual-chamber pacemakers frequently document atrial fibrillation (AF) in patients without symptoms. Pacemaker-detected AF is associated with a 2.5-fold increased risk of stroke, although it is not established whether oral anticoagulation reduces this risk. This study sought to determine the prevalence and predictors of pacemaker-detected AF and to document current oral anticoagulant use.

Methods

A retrospective analysis included all patients from a single academic hospital who had pacemakers capable of documenting AF. Blinded evaluation of all echocardiograms conducted within 6 months of implantation was performed.

Results

Of 445 patients, pacemaker-detected AF was present in 246 (55.3%), who were older (74.3 ± 13.7 years vs 71.7 ± 14.4, P = 0.046), more likely to have a history of clinical AF (29.7% vs 19.1%, P = 0.01), and had a larger left atrial volume index (34.4 ± 11.8 mL/m² vs 30.0 ± 9.9 mL/m², P = 0.019) than the patients without pacemaker-detected AF. Among patients without a clinical history of AF, left atrial volume index was higher among those with pacemaker-detected AF (33.7 ± 11.3 mL/m² vs 29.0 ± 10.1 mL/m², P = 0.034). Anticoagulants were used in 35.3% of patients with pacemaker-detected AF, compared with 21.6% of patients without (P < 0.05). In patients with pacemaker-detected AF, anticoagulants were used more frequently among patients who also had clinical AF (58.9%) compared with those without (23.7%, P < 0.001).

Conclusions

Pacemaker-detected AF occurs in 50% of pacemaker patients and is treated with anticoagulants in less than 25% of patients who do not have a history of clinical AF. Clinical trials are needed to determine the role of anticoagulation in this population.     

Impact of atrial fibrillation on tricuspid and mitral annular dilatation and valvular regurgitation.

To investigate the effects of atrial fibrillation (AF) on the mitral and tricuspid valves, the corresponding annular dilatation and valvular regurgitation were compared with 2-dimensional and Doppler echocardiography in 31 consecutive patients with lone AF and 28 normal controls. Mid-systolic mitral and tricuspid annular areas were measured from 2 diameters in 2 orthogonal apical echocardiograms. Percent (%) mitral regurgitant (MR) or tricuspid regurgitant (TR) jet area to the left or right atrial area was evaluated and % MR or TR jet area >20% was considered moderate or significant. Both the mitral and tricuspid annular areas in patients with lone AF were significantly larger compared with the controls (mitral: 9.5 +/- 1.2 vs 6.6 +/- 0.9 cm2, lone AF vs control, p < 0.01) (tricuspid: 12.0 +/- 2.0 vs 7.5 +/- 0.9 cm2, p < 0.01). The % increase in the annular area relative to the mean normal value was significantly greater in the tricuspid valve (44 +/- 18 vs 60 +/- 28%, p < 0.01). Moderate or severe MR was not observed and the incidence of moderate or severe valve regurgitation (% jet area >20%) was significantly higher in the tricuspid valve (0/31 vs 11/31, MR vs TR, p < 0.01) in patients with lone AF. The % TR jet area showed significant correlation with tricuspid annular area (r2 = 0.65, p < 0.001). Lone AF is associated with annular dilatation of both mitral and tricuspid valves, but the annular dilatation and valvular regurgitation are significantly greater in the tricuspid valve.     

Adverse Effects of Continuous Ventricular Pacing in Patients with Slower Atrial Fibrillation and Normal Left Ventricular Systolic Function

Background: Both heart rate irregularity during chronic atrial fibrillation (AF) and ventricular desynchronization imposed by ventricular pacing may compromise ventricular function. We investigated whether heart rhythm regularization achieved through ventricular overdrive pacing (VP) gives additional benefit over rate control alone in patients with AF. Methods: We studied 27 patients (mean age 72 ± 7 years) with AF and normal left ventricular (LV) systolic function who were implanted with a common VVIR pacemaker. Cardiac function was assessed by using serial echocardiographic conventional, tissue Doppler imaging (TDI) and color M‐Mode (CMM) examinations, together with B‐type natriuretic peptide (BNP) measurements. Baseline data were obtained during AF (mean heart rate 58 ± 5 beats/minute) with the pacemakers programmed to ventricular mere back‐up pacing. These data were compared to the corresponding measurements following a 2‐week VP period after the devises had been programmed to a lower rate of 70 beats/min, ensuring most of the time continuing VP. Results: Continuous VP compared to AF, reduced the LV cardiac index (2.28 ± 0.44 l/min/m² vs 2.33 ± 0.39 l/min/m², P < 0.05), increased the LV end‐systolic volume (38 ± 14 mL vs 35 ± 11 mL, P < 0.05), and decreased the TDI‐derived systolic and diastolic mitral velocity (8.1 ± 1.8 cm/s vs 8.3 ± 1.6 cm/s, and 8.1 ± 1.8 cm/s vs 8.3 ± 1.6 cm/s, respectively, both P < 0.05) and the CMM‐derived transmitral early diastolic flow propagation velocity (37.6 ± 9.2 vs 41.5 ± 9.7, P < 0.05). Following VP, both ratios E/Ea and E/Vp showed a trend toward increase (P = NS), whereas BNP rose up to 25.5% (median value, from 111 pg/mL to 165 pg/mL, P < 0.01). Conclusion: VP may be considered disadvantageous compared to slower AF.     

Acute and long-term effects of atrioventricular junction ablation and VVIR pacemaker in symptomatic patients with chronic lone atrial fibrillation and normal ventricular response

INTRODUCTION: The precise role of irregular ventricular response in atrial fibrillation (AF) has not been fully elucidated. This study examined the independent effects of rhythm regularity in patients with chronic AF. METHODS AND RESULTS: This study included 50 patients who had chronic lone AF and a normal ventricular rate. Among these patients, 21 who underwent AV junction ablation and implantation of a VVIR pacemaker constituted the ablation group; the other 29 patients were the medical group. Acute hemodynamic findings were measured in 21 ablation patients before ablation (during AF, baseline) and 15 minutes after ablation (during right ventricular pacing). Compared with baseline data, ablation and pacing therapy increased cardiac output (4.7 +/- 0.8 vs 5.2 +/- 0.9 L/min; P = 0.05), decreased pulmonary capillary wedge pressure (16 +/- 5 vs 13 +/- 4 mmHg; P = 0.001), and decreased left ventricular end-diastolic pressure (14 +/- 4 vs 11 +/- 3 mmHg; P < 0.05). After 12 months, the ablation group patients showed lower scores in general quality of life (-20%; P < 0.001), overall symptoms (-24%; P < 0.001), overall activity scale (-23%; P = 0.004), and significant increase of left ventricular ejection fraction (44% +/- 6% vs 49% +/- 5%; P = 0.02) by echocardiographic examination. CONCLUSION: AV junction ablation and pacing in patients with chronic AF and normal ventricular response may confer acute and long-term benefits beyond rate control by eliminating rhythm irregularity.     

Decreased right ventricular function after coronary artery bypass grafting

Decreased right ventricular function after coronary artery bypass grafting is a common and well-known (if not well-understood) phenomenon.We prospectively evaluated right ventricular function via echocardiographic tricuspid annular motion, tricuspid annular velocity, and right ventricular strain analysis before and after coronary artery bypass grafting. We also evaluated the effect of right coronary artery disease and revascularization on post-coronary artery bypass grafting, right ventricular function, and interventricular septal motion.We performed baseline echocardiography in 250 candidates for coronary artery bypass grafting, and we repeated echocardiography in 240 of those patients 1 year after coronary artery bypass grafting. We evaluated right ventricular function via tricuspid annular motion, tricuspid annular velocity, and right ventricular strain analysis, all measured at the right ventricular free wall.Right ventricular function as evaluated by tricuspid annular motion showed a significant reduction 1 year after coronary artery bypass grafting (21.7 vs 12.1 mm; P < 0.001) compared with preoperative measurements. Right ventricular tissue velocity (14.0 vs 7.0 cm/s; P < 0.001) and right ventricular strain (20.3% vs 11.6%; P < 0.001) were also significantly reduced after coronary artery bypass grafting. Interventricular septal motion was paradoxical in 97% of the patients 1 year after coronary bypass.Right ventricular function remained depressed for as long as 1 year after coronary artery bypass grafting. These findings were independent of the state of the right coronary artery and the graft. It is likely that the interventricular septum is recruited to maintain right ventricular stroke volume after coronary artery bypass grafting.     

Determinants of the severity of functional tricuspid regurgitation

We performed a prospective study of patients with chronic right ventricular (RV) dilation to determine the factors associated with the degree of functional tricuspid regurgitation (FTR). We prospectively enrolled 64 patients with chronic RV dilation and measured right atrial (RA) area, RV area and its fractional area change (RVFAC), tricuspid annular diameter and contraction, tricuspid valve (TV) tethering area, and systolic pulmonary artery pressure. We also measured the RV eccentricity index and the RV sphericity index for simple presentation of RV geometry. Regurgitant orifice area of FTR was obtained for the quantification of FTR. End-systolic RV eccentricity index (r=0.73), end-diastolic RV eccentricity index (r=0.56), RA area (r=0.49), TV tethering area (r=0.37), age (r=0.31), end-systolic (r=0.42) and end-diastolic (r=0.30) tricuspid annular diameters, and left ventricular ejection fraction (r=-0.37) were significantly related to the regurgitant orifice area of FTR in univariate analysis. However, RV area, RVFAC, and systolic pulmonary artery pressure were not. In multivariate analysis, the end-systolic RV eccentricity index (p<0.001), TV tethering area (p=0.003), and end-diastolic tricuspid annulus diameter (p=0.007) showed the independent associations with regurgitant orifice area of FTR. The sensitivities and specificities for predicting more than mild FTR were found to be 79% and 82% with an end-systolic RV eccentricity index>2.0, 69% and 73% with an end-systolic tethering area>1.0 cm2, and 64% and 59% for an end-systolic tricuspid annulus diameter>3.9 cm, respectively. FTR severity was found to show the best correlation with the end-systolic RV eccentricity index. In conclusion, these findings underscore the importance of eccentric RV dilation for determining FTR severity and should lead to the development of more rational surgical approaches to FTR beyond TV annuloplasty.     

Reduced atrial contribution to left ventricular filling in patients with severe tricuspid regurgitation after tricuspid valvulectomy: a Doppler echocardiographic study

Patients undergoing valvulectomy for isolated tricuspid valve endocarditis offer the unique opportunity to study the effects of acquired right ventricular volume overload on left ventricular filling in persons free of pulmonary hypertension and preexisting left heart disease. Eleven patients who had undergone total or partial removal of the tricuspid valve were compared with 11 age-matched control subjects; Doppler echocardiographic techniques were used to quantify changes in left ventricular filling and to relate them to changes in left ventricular and left atrial geometry caused by right ventricular and right atrial distension. The late diastolic fractional transmitral flow velocity integral, a measure of the left atrial contribution to left ventricular filling, was significantly decreased in patients undergoing tricuspid valvulectomy compared with control subjects (0.22 +/- 0.11 versus 0.32 +/- 0.09; p less than 0.04). Severe tricuspid regurgitation in these patients resulted in marked right atrial distension, reversal of the normal interatrial septal curvature and compression of the left atrium such that left atrial area was significantly smaller than in control subjects (5.9 +/- 2.2 versus 8.6 +/- 1.2 cm2/m2; p less than 0.005). Acting as a receiving chamber, the left ventricle was maximally compressed by the volume-overloaded right ventricle in late diastole, coincident with the timing of atrial systole, resulting in a significant increase in the left ventricular eccentricity index compared with that in control subjects (1.35 +/- 0.14 versus 1.03 +/- 0.1; p less than 0.001). Thus, right ventricular volume overload due to severe tricuspid regurgitation results in left heart geometric alterations that decrease left atrial preload, impair left ventricular receiving chamber characteristics and reduce the atrial contribution to total left ventricular filling.     

Morbid anatomy in neonates with Ebstein's anomaly of the tricuspid valve: pathophysiologic and clinical implications.

The hearts of six neonates with Ebstein's anomaly of the tricuspid valve who died in the 1st month of life were compared with hearts of six age- and size-matched control neonates. All six hearts had morphologically severe disease with gross right atrial dilation and marked apical displacement of the tricuspid valve. All had a secundum atrial septal defect and four had additional cardiac lesions (pulmonary atresia in two, ventricular septal defect in two). There was significant thinning of the right ventricular free wall distal to the tricuspid valve (3 +/- 0.2 mm vs. control 4.2 +/- 0.2, p less than 0.01) and right ventricular fiber diameter was reduced (7.2 +/- 0.3 microns vs. control 11.4 +/- 0.6, p less than 0.001). The fibrous tissue content of both right and left ventricular free walls was increased (right, 29.3 +/- 2.6% vs. control 8.7 +/- 1.1, p less than 0.001; left, 23.2 +/- 1.5% vs. control 8.5 +/- 0.7%, p less than 0.001). Although the right ventricular abnormalities might be explained by hemodynamic stress in utero, abnormalities of the left ventricular free wall suggest that either genetic or nonhemodynamic environmental factors are involved in the morphogenesis of this condition. Increased right and left ventricular fibrosis may contribute to the poor early outcome in this group and may predispose to late complications, such as subnormal exercise performance, hemodynamic deterioration or late sudden death that may occur in patients with Ebstein's anomaly who survive the neonatal period.     

Limitations of scintigraphically determined left-ventricular/right-ventricular stroke volume in the evaluation of the severity of aortic valve insufficiency

Noninvasive evaluation of aortic regurgitation can be performed by the radionuclide determination of the left/right ventricular stroke volume ratio. This ratio proved to have a relatively low sensitivity. Therefore, we conducted a study comprising 25 patients with angiographically verified aortic regurgitation in order to look for characteristics of patients with false-negative results. In 5 patients with aortic regurgitation the scintigraphically determined left/right ventricular stroke volume ratio was within normal range. In 3 other patients with severe regurgitation the radionuclide ratio was distinctly lower when compared with the angiographic stroke volume ratio (calculated from the left ventricular stroke volume and effective stroke volume). Left heart failure was observed in all these 8 patients, 7 of 8 patients showed additional right heart failure. Only 2 of the other 17 patients had signs of left heart failure. In the 8 patients with discrepant results, the roentgenographically determined heart volume was increased (1617 vs 1057 ml; 2p less than 0.001), left ventricular ejection fraction decreased (31 vs 60%; 2p less than 0.001), and mean pulmonary artery and right atrial pressure were elevated (38 vs 18 mm Hg; 2p less than 0.001; 11 vs 6 mm Hg; 2p less than 0.001). We conclude that in patients with aortic regurgitation, congestive heart failure associated with functional pulmonic and tricuspid regurgitation and geometric reasons can lead to a reduced sensitivity of the radionuclide left/right ventricular stroke volume ratio.     

A novel finding of the atrial substrate properties and long-term results of catheter ablation in chronic atrial fibrillation patients with left atrial spontaneous echo contrast

Atrial Substrate Properties in Chronic AF Patients with LASEC. Background: The atrial substrate in chronic atrial fibrillation (AF) patients with a left atrial spontaneous echo contrast (LASEC) has not been previously reported. The aim of this study was to investigate the atrial substrate properties and long‐term follow‐up results in the patients who received catheter ablation of chronic AF. Methods: Of 36 consecutive patients with chronic AF who received a stepwise ablation approach, 18 patients with an LASEC (group I) were compared with 18 age‐gender‐left atrial volume matched patients without an LASEC (group II). The atrial substrate properties including the weighted peak‐to‐peak voltage, total activation time during sinus rhythm (SR), dominant frequency (DF), and complex fractionated electrograms (CFEs) during AF in the bi‐atria were evaluated. Result: The left atrial weighted bipolar peak‐to‐peak voltage (1.0 ± 0.6 vs 1.6 ± 0.7 mV, P = 0.04), total activation time (119 ± 20 vs 103 ± 13 ms, P < 0.001) and DF (7.3 ± 1.3 vs 6.6 ± 0.7 Hz, P < 0.001) differed between group I and group II, respectively. Those parameters did not differ in the right atrium. The bi‐atrial CFEs (left atrium: 89 ± 24 vs 92 ± 25, P = 0.8; right atrium: 92 ± 25 vs 102 ± 3, P = 0.9) did not differ between group I and group II, respectively. After a mean follow‐up of 30 ± 13 month, there were significant differences in the antiarrhythmic drugs (1.1 ± 0.3 vs 0.7 ± 0.5, P = 0.02) needed after ablation, and recurrence as persistent AF (92% vs 50%, P = 0.03) between group I and group II, respectively. After multiple procedures, there were more group II patients that remained in SR, when compared with group I (78% vs 44%, P = 0.04). Conclusion: There was a poorer atrial substrate, lesser SR maintenance after catheter ablation and need for more antiarrhythmic drugs in the chronic AF patients with an LASEC when compared with those without an LASEC. (J Cardiovasc Electrophysiol, Vol. pp. 1‐8)     

Echocardiographic serial changes of hypertensive cardiomyopathy with severely reduced ejection fraction: comparison with idiopathic dilated cardiomyopathy

Background:

Hypertensive cardiomyopathy with reduced ejection fraction (HTCMREF) is known as an important cause of reversible cardiomyopathy, but its serial changes on echocardiography is yet to be elucidated.

Hypothesis:

HTCMREF on serial echocardiography has distinctive points as compared to idiopathic dilated cardiomyopathy (idDCM).

Methods:

We retrospectively studied 18 hypertensive patients (mean age, 63 ± 13 years, 56% women) admitted with severe left ventricular (LV) systolic dysfunction and heart failure. We compared clinical characteristics and echocardiographic parameters at admission and follow‐up between the patients with HTCMREF and 18 age‐matched patients with idDCM. Left ventricular mass (LVM) and left atrial volume (LAV) were calculated by a formula using echocardiographic measurement.

Results:

In HTCMREF, left ventricular ejection fraction improved to 52.3 ± 8.8% during a mean follow‐up of 574 days. In HTCMREF, initial left atrial diameter was greater than in idDCM (43.6 ± 5.8 mm vs 38.9 ± 6.3, p = 0.027). At follow‐up, LAV index decreased in HTCMREF (from 31.9 ± 8.3 mL/m² to 21.0 ± 8.9, P < 0.001), as opposed to a significant increase in idDCM (from 28.5 ± 10.9 mL/m² to 31.9 ± 8.3, P < 0.001). There was no significant difference in initial LVM index between the 2 groups, but only in HTCMREF did LVM index decrease significantly (151.4 ± 42.1 g/m² from 192.2 ± 43.7, P < 0.01) at follow‐up. In HTCMREF, LV wall on M‐mode was thicker than in idDCM.

Conclusions:

Hypertensive cardiomyopathy with severe LV systolic dysfunction might be characterized by eccentric left ventricular hypertrophy and enlarged left atrium in comparison with idDCM. Clin. Cardiol. 2012 doi: 10.1002/clc.22012 The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Is systemic right ventricular function by cardiac MRI related to the degree of tricuspid regurgitation in congenitally corrected transposition of the great arteries?

Background and Methods

Systemic right ventricular dysfunction and tricuspid regurgitation (TR) are frequently encountered in patients with congenitally corrected transposition of the great arteries (CCTGA). Studies using echocardiography have suggested a relationship between the degree of TR and systemic right ventricular dysfunction; however, assessment of systemic right ventricular function by echocardiography is limited. Cardiac MRI (CMR) is the gold standard for volumetric assessment of the systemic right ventricle. We performed a retrospective cohort study at our center evaluating all adult patients with CCTGA who underwent a CMR between 1/1999 and 1/2013 to determine the relationship between the degree of TR and systemic right ventricular function.

Results

Of the 33 patients identified, 12 had ≤ mild TR (37%), 13 had moderate TR (40%), and 8 had severe TR (24%). Mean age at CMR was 38 years (23–64). Mean right ventricular ejection fraction (45% vs. 41% vs. 42%, p = 0.68) and mean indexed right ventricular end diastolic volume (122 ml/m² vs. 136 ml/m² vs. 138 ml/m²p = 0.36) were not significantly different for patients with ≤ mild TR, moderate TR or severe TR. The degree of TR was not associated with additional congenital lesions, prior procedures, presence of an intraventricular conduction delay, or decreased left ventricular function.

Conclusion

No association between the degree of TR and right ventricular volume or ejection fraction by CMR was identified. Failure to show worsening function or increased volume with greater degrees of TR suggests that the degree of regurgitation alone may not fully explain the heterogeneity in right ventricular size and function.     

Effects of cavotricuspid isthmus catheter ablation on paroxysmal atrial fibrillation

It has been demonstrated that successful cavotricuspid isthmus ablation of typical atrial flutter combined with atrial fibrillation (AF) sometimes influences the preablation history of paroxysmal AF. However, the effectiveness of only isthmus ablation on AF itself is unclear. Endocardial catheter mapping during induced AF was performed around the tricuspid annulus using duodecapolar clectrode catheters in 39 patients with drug-refractory paroxysmal AF. Isthmus ablation was performed in 16 patients (41%) in whom catheter mapping during AF showed an organized activation pattern around the tricuspid annulus. During a mean follow-up of 12.3 months, isthmus ablation was successful in preventing AF in 12 (75%) patients, 8 without medication and 4 with a previously ineffective drug. This success group had a significantly higher F wave amplitude in lead V1 (0.29+/-0.10 vs 0. 15+/-0.04 mV, p < 0.01), a higher left ventricular ejection fraction (74+/-9 vs 58+/-2%, p < 0.05), and a smaller left atrial dimension (35+/-6 vs 43+/-4 mm, p < 0.05) than the failure group. Isthmus ablation may be effective in preventing paroxysmal AF with an organized activation pattern around the tricuspid annulus. F wave amplitude, left ventricular ejection fraction, and left atrial dimension were significant predictors of success.     

Long‐Term Outcome of Catheter Ablation in Patients with Atrial Fibrillation Originating from Nonpulmonary Vein Ectopy

Long‐Term Outcome of NPV AF Ablation . Introduction: Data regarding the long‐term outcome of catheter ablation in patients with nonpulmonary vein (NPV) ectopy initiating atrial fibrillation (AF) are limited. We aimed to evaluate the long‐term result of patients with AF who had NPV triggers and underwent catheter ablation. Methods and Results: The study included 660 consecutive patients (age 54 ± 11 years old, 477 males) who had undergone catheter ablation for AF. Group 1 consisted of 132 patients with AF initiating from the NPV, and group 2 consisted of 528 patients with AF initiating from pulmonary vein (PV) triggers only. Patients from Group 1 were younger than those from Group 2 (51 ± 12 years old vs 54 ± 11 years old, P = 0.001) and were more likely to be females (34.4% vs 25.8%, P = 0.049). The incidences of nonparoxysmal AF (36.4% vs 16.3%, P < 0.001) and right atrial (RA) enlargement (31.3% vs 19%, P = 0.004) were higher, and the biatrial substrates were worse in Group 1 than those in Group 2 (left atrial voltage 1.5 ± 0.7 mV vs 1.9 ± 0.7 mV, P < 0.001, RA voltage 1.6 ± 0.5 mV vs 1.8 ± 0.6 mV, P = 0.014). During a follow‐up period of 46 ± 23 months, there was a higher AF recurrence rate in Group 1 than in Group 2 (57.6% vs 38.8%, P < 0.001). The independent predictors of AF recurrence were NPV trigger (P < 0.001, HR 2, 95% CI 1.4–2.85), nonparoxysmal AF (P = 0.021, HR 1.55, 95% CI 1.07–2.24), larger left atrial diameter (P = 0.002, HR 1.04, 95% CI 1.02–1.07) and worse left atrial substrate (P = 0.028, HR 1.3, 95% CI 1.03–1.64). Conclusion: Compared to AF originating from the PV alone, AF originating from the NPV ectopy showed a worse outcome. (J Cardiovasc Electrophysiol, Vol. 24, pp. 250‐258, March 2013)