Assessment of Right Ventricular Diastolic Function by Tissue Doppler Imaging in Patients with Acute Right Ventricular Myocardial Infarction

Background: It is known that right ventricular systolic parameters as assessed by color tissue Doppler imaging (TDI) are abnormal in patients with inferior wall ST elevation myocardial infarction (IWMI) with right ventricular myocardial infarction (RVMI). This study was undertaken to determine right ventricular diastolic function as assessed by TDI in patients with acute RVMI. Methods: Thirty‐five patients with first IWMI were studied and compared with 20 age‐matched healthy controls, and categorized into those with (14 patients) and without (21 patients) RVMI based on standard ECG criteria. Peak systolic, peak early and late diastolic velocities (Sm, Em, and Am), Em/Am ratio along with time to Sm (ECG Q‐Sm) and time to Em (ECG Q‐Em) were acquired from the apical 4‐chamber view at the lateral side of tricuspid annulus using TDI. Results: Sm, Em, and Em/Am ratio was reduced significantly in patients with RVMI as compared with those without RVMI and healthy individuals (Sm [11.1 ± 2.9] vs. [14 ± 1.9] and [14.5 ± 2.1] cm/sec, P < 0.01; Em [9.2 ± 3.5] vs. [12.9 ± 3] and [14.0 ± 2.0] cm/sec, P < 0.01; Em/Am ratio 0.53 ± 0.2 vs. 0.78 ± 0.19 and 0.8 ± 0.3 [P < 0.0001]). Among the intervals, there was significant prolongation of Q‐Em (558 ± 14.8 vs. 507 ± 16.2 and 480 ± 20 ms [P < 0.0001]) but Q‐Sm and Am were not statistically different between the groups. Conclusion: Right ventricular TDI diastolic parameters are abnormal in patients with RVMI. The method of recording the velocities and time intervals are simple and can be used to assess right ventricular diastolic function in patients with RVMI. (Echocardiography 2010;27:539‐543)     

Recovery of Long‐Axis Left Ventricular Function after Aortic Valve Replacement in Patients with Severe Aortic Stenosis

Background: Patients with aortic stenosis (AS) should undergo aortic valve replacement (AVR) before irreversible LV dysfunction has developed. Assessment of long‐axis left ventricular (LV) function may assist in proper timing of AVR. Objectives: To assess serial changes in long‐axis LV function before and after AVR in patients with severe AS and preserved LV ejection fraction. Methods: The study comprised 27 consecutive patients (mean age 64.9 ± 11.7 years, 15 males) with symptomatic severe AS, scheduled for AVR. Seventeen subjects without known cardiac disease, matched for age, gender, LV ejection fraction and cardiovascular risk factors, served as a control group. Long‐axis LV function assessment was done with tissue Doppler imaging at 3 weeks, 6 months, and 12 months after AVR. Results: Mean aortic valve area in the AS group was 0.70 ± 0.24 cm². Pre‐AVR peak systolic mitral annular velocities were significantly lower compared to controls (6.7 ± 1.5 vs. 8.9 ± 2.0 cm/s, P < 0.05). Post‐AVR peak systolic mitral annular velocities improved to 9.1 ± 2.9 at 3 weeks, 8.6 ± 2.7 at 6 months, and 8.1 ± 1.7 cm/s at 12 months (P < 0.05). Improvements were seen over the whole range of pre‐AVR peak systolic mitral annular velocities. Patients with improved Sm after AVR (defined as ≥10% compared to baseline values) did not differ in baseline characteristics as compared to those who did not improve. Conclusions: In patients with severe AS and preserved LV ejection fraction, abnormal systolic mitral annular velocities improve after AVR, independent of the pre‐AVR value. (Echocardiography 2010;27:1177‐1181)     

Long‐Term Mechanical Consequences of Permanent Right Ventricular Pacing: Effect of Pacing Site

Optimal Right Ventricular Pacing Introduction: Long‐term right ventricular apical (RVA) pacing has been associated with adverse effects on left ventricular systolic function; however, the comparative effects of right ventricular outflow tract (RVOT) pacing are unknown. Our aim was therefore to examine the long‐term effects of septal RVOT versus RVA pacing on left ventricular and atrial structure and function. Methods: Fifty‐eight patients who were prospectively randomized to long‐term pacing either from the right ventricular apex or RVOT septum were studied echocardiographically. Left ventricular (LV) and atrial (LA) volumes were measured. LV 2D strain and tissue velocity images were analyzed to measure 18‐segment time‐to‐peak longitudinal systolic strain and 12‐segment time‐to‐peak systolic tissue velocity. Intra‐LV synchrony was assessed by their respective standard deviations. Interventricular mechanical delay was measured as the difference in time‐to‐onset of systolic flow in the RVOT and LV outflow tract. Septal A’ was measured using tissue velocity images. Results: Following 29 ± 10 months pacing, there was a significant difference in LV ejection fraction (P < 0.001), LV end‐systolic volume (P = 0.007), and LA volume (P = 0.02) favoring the RVOT‐paced group over the RVA‐paced patients. RVA‐pacing was associated with greater interventricular mechanical dyssynchrony and intra‐LV dyssynchrony than RVOT‐pacing. Septal A’ was adversely affected by intra‐LV dyssynchrony (P < 0.05). Conclusions: Long‐term RVOT‐pacing was associated with superior indices of LV structure and function compared with RVA‐pacing, and was associated with less adverse LA remodeling. If pacing cannot be avoided, the RVOT septum may be the preferred site for right ventricular pacing. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1120‐1126)     

Assessment of Left Ventricular Systolic Asynchrony in Patients with Clinical Hypothyroidism

Background: Hypothyroidism has a large number of adverse effects on the cardiovascular system such as impaired cardiac contractility. Left ventricular (LV) asynchrony is defined as loss of the simultaneous peak contraction of corresponding cardiac segments. Objective: To assess systolic asynchrony in patients with overt hypothyroidism. Methods: Asynchrony was evaluated in 31 patients with overt hypothyroidism and 26 controls. Clinical hypothyroidism was defined as serum thyroid‐stimulating hormone (TSH) more than 4.2 μIU/mL with reduced free T4 less than 1.10 ng/dL. All the patients and controls were subjected to an echocardiographic study including tissue synchronization imaging (TSI). The time to regional peak systolic velocity (Ts) in LV via the six‐basal‐six‐mid‐segmental model was measured on ejection phase TSI images, and four TSI parameters of systolic asynchrony were computed. LV asynchrony was described by these four TSI parameters. Results: The demographic characteristics and conventional echocardiographic parameters of both groups were similar (except total and LDL cholesterol, TSH, free T3, and free T4). All TSI parameters of LV asynchrony were prolonged in hypothyroid patients compared to controls. The standard deviation (SD) of the 12 LV segments Ts was (53.5 ± 14.1 vs. 29.3 ± 15.5, P < 0.0001); the maximal difference in Ts between any 2 of the 12 LV segments was (154.5 ± 37.3 vs. 91.9 ± 45.2, P < 0.0001); the SD of Ts of the 6 basal LV segments was (47.9 ± 15.9 vs. 27.1 ± 16.4, P < 0.0001); and the maximal difference in Ts between any 2 of the 6 basal LV segments was (118.4 ± 37.9 vs. 69.3 ± 39.0, P < 0.0001). The prevalence of LV asynchrony was significantly higher in patients with hypothyroidism compared with controls (83.9% vs. 26.9%, P < 0.0001). Conclusion: Patients with overt hypothyroidism show evidence of LV asynchrony by TSI. (ECHOCARDIOGRAPHY 2010;27:117‐122)     

The Impacts of Transcatheter Occlusion for Congenital Atrial Septal Defect on Left Ventricular Systolic Synchronicity: A Three‐Dimensional Echocardiography Study

Objectives: To investigate the impacts of transcatheter occlusion for congenital atrial septal defect (ASD) on left ventricular (LV) systolic synchronicity using a real time three‐dimensional echocardiography (RT3DE). Methods: Thirty patients with ASD closure were recruited for the study. Realtime three‐dimensional echocardiographic data sets were acquired for the measurement of LV volumes LV ejection fractions and LV three‐dimensional systolic synchronicity before and at 6 months after transcatheter occlusion for ASD. M‐mode echocardiography and RT3DE were performed to characterize interventricular septal (IVS) motion. Results: There were no differences in LV systolic synchronicity between before and after transcatheter closure of ASD (Tmsv‐16SD%: 5.6%± 1.4% vs 5.8%± 1.8%, P > 0.05; Tmsv—12SD%: 5.2 ± 1.1% vs 5.4 ± 1.2%, P > 0.05). But the abnormal IVS motion was found before device closure and normalized after transcatheter occlusion for ASD using M‐mode echocardiography and the excursion‐time figure (bull's‐eye derived from RT3DE); At the same time, LV ejection fraction (59.8 ± 2.6 vs 66.7 ± 5.9, P < 0.05) stroke volume (49 ± 14 vs 63 ± 11, P < 0.05) was improved significantly as well as normalization of IVS motion after transcatheter occlusion for ASD. The correlation between ASD diameter and change of LVEF is significant (r = 0.85, P < 0.001). Conclusion: Although transcatheter occlusion did not significantly impact on intrinsic LV systolic synchronicity in patients with ASD, LV systolic function can be improved through normalization of IVS abnormal motion after transcatheter ASD occlusion. (Echocardiography 2010;27:324‐328)     

Acute Effects of Single‐site Pacing from the Left and Right Ventricle on Ventricular Function and Ventricular–Ventricular Interactions in Children with Normal Hearts

Objective. We studied, as a physiological benchmark, acute effects of right ventricular (RV) apical, RV outflow, and left ventricular (LV) pacing in children with normal cardiac function on LV and RV function and ventricular–ventricular interactions. Design. The design of the study was a prospective, acute intervention. Setting. The study was conducted in a tertiary care electrophysiology laboratory. Population and Methods. Seven children (mean ± SD, 12 ± 4 years) were paced after accessory pathway ablation, at baseline (AOO), and with atrioventricular pacing (DOO) from the RV apex, RV outflow, and left ventricle. Outcome Measures. Right ventricular dP/dT_max and RV dP/dT_neg (high‐fidelity transducer‐tipped catheters, Millar Instruments, Houston, TX, USA), cardiac index (Fick), blood pressure, and QRS duration were measured at each pacing condition. Intra‐ and interventricular mechanical dyssynchrony, systolic‐ and diastolic peak tissue velocities, and isovolumic acceleration were recorded by tissue Doppler imaging at the lateral mitral, septal, and tricuspid annuli at each condition. Results at each pacing condition were compared by repeated‐measures analysis of variance. Results. Pacing prolonged QRS duration, causing electrical dyssynchrony (86 ± 19 ms [baseline], 141 ± 44 ms [RV apex], 121 ± 18 ms [RV outflow], and 136 ± 34 ms [LV], P < .01). Right ventricular outflow pacing caused LV intraventricular delay (63 ± 52 vs. 12 ± 7 ms, P < .05). Right ventricular apical pacing caused interventricular delay (61 ± 29 vs. 25 ± 18 ms, P < .05). There were no significant changes in blood pressure, cardiac index, RV dp/dT_max, RV dP/dT_neg, regional tissue velocities, or isovolumic acceleration during any of the pacing conditions, indicating preserved ventricular function and hemodynamics. No important ventricular–ventricular interactions were seen. Conclusions. In children with normal cardiac anatomy and function, single‐site RV apical, RV outflow, and LV pacing induce electromechanical dyssynchrony without significantly changing ventricular function or hemodynamics, or adversely affecting ventricular–ventricular interactions.     

Preoperative Right Ventricular Function in Patients with Organic Mitral Regurgitation

Aims: To assess the right ventricular (RV) function in patients with severe mitral regurgitation (MR); to find a relation between preoperative and postoperative parameters. Methods: RV function was echocardiographically assessed by determining the tricuspid annular plane systolic excursion (TAPSE) and the peak systolic velocity of the lateral tricuspid annulus (Sa) in 45 patients with severe organic MR (53.3% men, age 58 ± 10 years). Mean NYHA class was 2.6 ± 0.4, LVEF was 55.3 ± 12%, RV end‐diastolic diameter was 28.7 ± 4.7, left ventricular end‐systolic diameter (LVESD) was 44.6 ± 12.6 mm, and LV end‐diastolic volume (Simpson) was 160.6 ± 50.3 ml. All patients underwent mitral valve replacement with posterior chordal sparing. Results: Mean preoperative TAPSE and Sa were 19.4 ± 4.3 mm and 10.3 ± 3 cm/sec, respectively. RV dysfunction, defined as TAPSE < 22 mm, had 66.6% of the patients, and Sa < 11 cm/sec was found in 62.2% of the patients preoperatively. Preoperative TAPSE and Sa were significantly correlated (P < 0.00001, r = 0.61). Both TAPSE and Sa were correlated with the RV end‐diastolic diameter (P < 0.01), LVESD (P < 0.05) left ventricular dp/dt (P < 0.05), and LVEF (P < 0.0001). Postoperative LVEF was 50% (P < 0.001), Sa 5.3 ± 2 cm/sec (P < 0.001), and TAPSE 8.7 ± 3.2mm (P < 0.001). Twenty‐one patients (46.6%) reached the study end point of decrease of LVEF by more than 10%. Univariate predictors were age (P = 0.04), male gender (P = 0.01), TAPSE (P = 0.007), and Sa (P = 0.009), while a trend was found for regurgitation fraction (P = 0.058) and LV end‐diastolic volume index (P = 0.09). By multivariate analysis, TAPSE (P = 0.01) and Sa (P = 0.01) were predictive for the study end point. Conclusion: The assessment of the RV function by echocardiography is a simple tool that provides prognostic information in patients with MR. (Echocardiography 2010;27:282‐285)     

Left Ventricular Torsion Parameters are Affected by Acute Changes in Load

Background: Quantification of left ventricular torsion may provide new indices of systolic and diastolic function. We sought to characterize the effect of acute manipulation of load on cardiac torsion, plecotropy in human subjects. Methods: Simultaneous Millar LV pressure, micromanometry, and echocardiograms were performed on 18 patients (10 male, mean age 66 years) with normal systolic function. Loading was altered sequentially by the administration of glyceryl trinitrate (GTN) and saline fluid loading. Echocardiographic speckle tracking imaging was used to quantify LV torsion and event timing was recorded relative to mitral valve opening (MVO). Results: GTN administration decreased preload (LV end diastolic pressure: 15.7 vs 8.4 mmHg, P < 0.001), and afterload (wall stress: 140 vs 84 ×10³dyn/cm², P < 0.02). Administration of fluid increased preload (LVEDP 11.3 vs 18.1 mmHg, P < 0.001) and increased wall stress, but to a lesser extent (102 vs 117 ×10³dyn/cm², P < 0.003). GTN administration augmented peak torsion (8.4 vs 11.0 deg, P < 0.05), increased systolic torsion velocity (46.6 vs 65.3deg/sec, P < 0.01) and resulted in earlier onset of untwisting (–105 vs –127ms, P < 0.05). Fluid loading decreased the proportion of untwisting prior to MVO (39.0 vs 31.0%, P < 0.05), untwisting acceleration (–750 vs –592deg/sec/sec, P < 0.05) and delayed the timing of peak untwisting (–37.0 vs 9.1ms, P < 0.01), but did not affect systolic torsion parameters. Conclusions: Left ventricular torsion parameters are sensitive to acute changes in load and therefore need to be interpreted in the context of current loading conditions. (ECHOCARDIOGRAPHY 2010;27:407‐414)     

Left Ventricular Hypertrophy Determines the Severity of Diastolic Dysfunction in Patients with Nonvalvular Atrial Fibrillation and Preserved Left Ventricular Systolic Function

Regression of left ventricular (LV) hypertrophy (LVH) is known to be related to a lower incidence of stroke in hypertensive patients with nonvalvular atrial fibrillation (NV-AF). However, its mechanism remains controversial. Recently, diastolic dysfunction (DD) was reported to be correlated with ischemic stroke in NV-AF. We hypothesized that hypertension (HTN) and resultant LVH might be associated with the severity of DD in NV-AF. Two hundred and ninety-four patients (204 males, age 66 ± 12 y) with NV-AF with preserved LV systolic function were included. Clinical and echocardiographic data were compared between patients with enlarged left atrial (LA) volume (n == 237) and patients with normal LA. Age (60 ± 12 vs. 67 ± 11 years), sex (male; 81 vs. 62%%), duration of NV-AF (4.1 ± 7.8 vs. 45.7 ± 49.0 months), brain natriuretic peptide (108.3 ± 129.3 vs. 236.1 ± 197.0 pg//mL), right ventricular systolic pressure (24.5 ± 5.5 vs. 33.1 ± 11.1 mmHg), mitral inflow velocity (E [77.4 ± 22.2 vs. 88.3 ± 22.0 cm//s]), LV mass index (LVMI [87.6 ± 22.2 vs. 105.1 ± 23.2 g//m²]), peak systolic mitral annular velocity (S' [7.2 ± 2.0 vs. 5.8 ± 1.8 cm//s]), and mitral inflow velocity to diastolic mitral annular velocity (E//E' [9.8 ± 3.4 vs. 12.1 ± 4.4]) were significantly different between the two groups, respectively (P < 0.05). In multivariate analysis, LVMI was independently correlated with increased LA volume (OR: 1.037 [95%% CI: 1.011–1.063], P < 0.05), whereas HTN was not. LA enlargement, which reflects the severity and chronicity of DD, is independently associated with LVH in patients with NV-AF. Therefore, regression of LVH with anti-hypertensive treatment may lead to improvement of diastolic function and favorable clinical outcomes in hypertensive patients with NV-AF.     

“Supranormal” Cardiac Function in Athletes Related to Better Arterial and Endothelial Function

Objective: Athlete's heart is associated with left ventricular (LV) hypertrophy (LVH), and “supranormal” cardiac function, suggesting that this is a physiological process. Hypertrophy alone cannot explain increase in cardiac function, therefore, other mechanisms, such as better ventriculo‐arterial coupling might be involved. Methods: We studied 60 male (21 ± 3 years) subjects: 27 endurance athletes, and a control group of 33 age‐matched sedentary subjects. We assessed global systolic and diastolic LV function, short‐ and long‐axis myocardial velocities, arterial structure and function and ventriculo‐arterial coupling, endothelial function by flow‐mediated dilatation, and amino‐terminal pro‐brain natriuretic peptide (NT‐proBNP) and biological markers of myocardial fibrosis and of oxidative stress. Results: Athletes had “supranormal” LV longitudinal function (12.4 ± 1.0 vs 10.1 ± 1.4 cm/s for longitudinal systolic velocity, and 17.4 ± 2.6 vs 15.1 ± 2.4 cm/s for longitudinal early diastolic velocity, both P < 0.01), whereas ejection fraction and short‐axis function were similar to controls. Meanwhile, they had better endothelial function (16.7 ± 7.0 vs 13.3 ± 5.3%, P < 0.05) and lower arterial stiffness (pulse wave velocity 7.1 ± 0.6 vs 8.8 ± 1.1 m/s, P = 0.0001), related to lower oxidative stress (0.259 ± 0.71 vs 0.428 ± 0.88 nmol/mL, P = 0.0001), with improved ventriculo‐arterial coupling (37.1 ± 21.5 vs 15.5 ± 13.4 mmHg.m/s³× 10³, P = 0.0001). NT‐proBNP and markers of myocardial fibrosis were not different from controls. LV longitudinal function was directly related to ventriculo‐arterial coupling, and inversely related to arterial stiffness and to oxidative stress. Conclusions: “Supranormal” cardiac function in athletes is due to better endothelial and arterial function, related to lower oxidative stress, with optimized ventriculo‐arterial coupling; athlete's heart is purely a physiological phenomenon, associated with “supranormal” cardiac function, and there are no markers of myocardial fibrosis. (Echocardiography 2010;27:659‐667)     

Electrical Delay in Apically Positioned Left Ventricular Leads and Clinical Outcome After Cardiac Resynchronization Therapy

Electrical Delay in Apically Positioned LV Leads. Introduction: In recent studies, an anatomical apical left ventricular (LV) lead pacing location has been associated with deleterious outcome after cardiac resynchronization therapy (CRT). The differential impact of the LV lead electrical location in these patients remains unknown. Methods and Results: Thirty‐one consecutive CRT patients (mean age 71.7 ± 12.7 years, 55% left bundle‐branch block [LBBB] morphology) with an apical LV lead and LV lead electrical delay (LVLED) were studied. Anatomical LV lead location was determined via review of coronary venography and chest radiographs. Electrical location was assessed through intraprocedural LVLED measurement. Patients were dichotomized into either “long” LVLED (LVLED ≥ 50% of QRS) or “short” LVLED groups (LVLED < 50%). Patients in the long LVLED group demonstrated significantly greater freedom from a primary composite endpoint of all‐cause death, heart failure hospitalization, and cardiac transplantation at 2 years (81% vs 30%, P = 0.007 vs short LVLED patients). Longer LVLED was also associated with more favorable LV remodeling (LV end‐systolic volume –41.9 ± 10.3 mL vs –4.3 ± 17.2 mL; P = 0.05), and greater improvement in LV ejection fraction (+9.4 ± 2.9% vs +2.3 ± 7.5%; P = 0.04). Even after multivariate adjustment, LVLED remained an independent predictor of the primary composite endpoint (HR 0.47, P = 0.031). Conclusions: Electrical lead localization, as estimated by LVLED ≥ 50%, is associated with improved long‐term clinical outcome and measures of LV remodeling in patients with apical LV leads. Intraprocedural LVLED assessment may provide incremental utility in targeting lead placement even in conventionally unfavorable anatomical segments. (J Cardiovasc Electrophysiol, Vol. 24, pp. 182‐187, February 2013)     

Left Ventricular Untwisting in Restrictive and Pseudorestrictive Left Ventricular Filling: Novel Insights into Diastology

Background: Conceptually, an ideal therapeutic agent should target the underlying mechanisms that cause left ventricular (LV) diastolic dysfunction. The objective of our study was to gain further insight into the mechanics of diastology by comparison of LV untwisting measured by speckle tracking echocardiography (STE) in young healthy adults with normal and “pseudorestrictive” LV filling, and dilated cardiomyopathy (DCM) patients with “true restrictive” LV filling. Methods: The study comprised 20 healthy volunteers with a Doppler LV‐inflow pattern compatible with restrictive LV filling but a diastolic early phase filling velocity/early diastolic velocity of the mitral annulus (E/Em) ratio <8 (“pseudorestrictive”), 20 for age and gender‐matched healthy volunteers with normal LV filling and an E/Em ratio <8, and 10 DCM patients with “true restrictive” LV filling and an E/Em ratio >15. LV untwisting parameters were determined by STE. Results: Compared to healthy subjects, DCM patients had decreased peak diastolic untwisting velocity (−62 ± 33 degrees/s vs −113 ± 25 degrees/s, P < 0.01) and untwisting rate (−15 ± 9 degrees/s vs −51 ± 24 degrees/s, P < 0.01). Compared to healthy subjects with normal LV filling, healthy subjects with “pseudorestrictive” LV filling had increased peak diastolic untwisting velocity (−123 ± 25 degrees/s vs −104 ± 30 degrees/s, P < 0.05) and untwisting rate (−59 ± 23 degrees/s vs −44 ± 22 degrees/s, P < 0.05). Conclusion: Faster LV untwisting plays a pivotal role in the rapid early diastolic filling occasionally seen in young healthy individuals. In contrast, in DCM patients untwisting is severely delayed and this impairment to utilize suction may reduce LV filling. (Echocardiography 2010;27:269‐274)     

Clinical utility of left ventricular strain,wall stress and serum brain natriuretic peptide levels in chronic hemodialysis patients

Background

Left ventricular (LV) global longitudinal strain (GLS) reliably assesses LV systolic function. The precise relation between LV wall stress and serum Brain natriuretic peptide (BNP) concentrations in hemodialysis (HD) patients needs to be clarified. BNP levels are raised in patients with end-stage renal disease (ESRD) and could reflect LV impairment among HD patients.

Assessment of Left Ventricular Function and Tei Index by Tissue Doppler Imaging in Patients with Slow Coronary Flow

Background: The aim of this study was to assess left ventricular (LV) function and the Tei index by tissue Doppler imaging (TDI), and also to evaluate the relationship of thrombolysis in myocardial infarction (TIMI) frame count (TFC) with the Tei index and LV function in patients with slow coronary flow (SCF). Methods: We prospectively evaluated 50 patients with SCF and 27 control subjects. Diagnosis of SCF was made by TFC. LV systolic and diastolic function was assessed by conventional echocardiography and TDI. Results: Early diastolic mitral annular velocity (Em), Em/Am, and peak systolic mitral annular velocity (Sm) were lower in patients with SCF than those in controls (13±2.8 cm/sec vs 15.2±2.8 cm/sec, P = 0.002; 0.88±0.22 vs 1±0.23, P = 0.03; and 14.1±3.51 vs 16.5±3.31, P = 0.005, respectively). In patients with SCF, the Tei index was significantly higher than that in controls (0.34±9.6 vs 0.29±9.5, P = 0.02, respectively). Mean TFC and RCA TFC were positively correlated with the Tei index (r = 0.3, P = 0.02 and r = 0.329, P = 0.02). Left circumflex (LCX) TFC was negatively correlated with Em/Am (r =–0.310, P = 0.03) only in patients with SCF. Conclusion: LV systolic and diastolic function is impaired in patients with SCF. TDI analysis of mitral annular velocities such as the Tei index, Em, Em/Am, and Sm is useful to assess LV systolic and diastolic dysfunction in patients with SCF. Mean TFC and RCA TFC were positively correlated with the Tei index and LCX TFC was negatively correlated with Em/Am. TDI may be better than conventional echocardiography in assessing LV function in patients with SCF. (ECHOCARDIOGRAPHY, Volume 26, November 2009)     

Left Ventricular Longitudinal Myocardial Function in Overt Hypothyroidism: A Tissue Doppler Echocardiographic Study

Background: The aim of this study was to assess left ventricular (LV) myocardial regional function in overt hypothyroidism by use of tissue Doppler imaging and to compare the results to the hormonal profile and standard Doppler echocardiographic examination. Methods: Hypothyroidic (Group 1, n = 25) and euthyroidic patients (Group 2, n = 25) underwent transthorasic echocardiography, strain and strain rate imaging. Results: Standard echocardiography showed that patients with overt hypothyroidism had significantly longer isovolumic contraction time (IVCT) (P < 0.05), deceleration time (DT) (P = 0.014) and isovolumic relaxation time (IVRT) (P = 0.022). Tissue Doppler imaging showed that the mean peak systolic strain (SI) (16.47 ± 1.45 vs. 20.63 ± 1.51, P < 0.001), the mean peak systolic strain rate (SSR) (1.05 ± 0.13 vs. 1.47 ± 0.11, P < 0.001), the mean peak early diastolic strain rate (ESr) (1.72 ± 0.38 vs. 2.03 ± 0.25, P < 0.05) and the mean peak late diastolic strain rate (ASr) (1.22 ± 0.31 vs. 1.46 ± 0.32, P < 0.05) were significantly lower in Group 1 compared to Group 2. For all patients, the systolic strain and systolic strain rate parameters negatively correlated with thyroid stimulating hormone levels and positively correlated with the levels of free triiodothyronine (fT₃) and free tetraiodothyronine (fT₄). Conclusion: These results indicate that overt hypothyroidism is associated with early impairment in LV longitudinal myocardial function, and that tissue Doppler echocardiography is useful for the grading of disease and detection of early impairment. (ECHOCARDIOGRAPHY 2010;27:505‐511)     

Usefulness of rate regulation through continuous ventricular pacing in patients with drug-controlled slower atrial fibrillation and normal or depressed left ventricular systolic function

We studied 33 clinically stable patients with permanent atrial fibrillation (AF), implanted with a ventricular demand rate-responsive (VVIR) pacemaker or an automatic defibrillator, in order to evaluate whether continuous right ventricular apex pacing (VP) conferring rate regulation may be advantageous when compared with slower drug-controlled AF. Devices were chronically programmed at ventricular backup pacing. Patients were divided in two groups according to their normal (n = 17) or depressed (n = 16) left ventricular systolic function (LVSF). Ventricular function was studied by using tissue Doppler and color M-mode and echocardiography, as well as B-type natriuretic peptide (BNP) measurements. Baseline data during AF were compared to corresponding measurements following a 1-month pacing period after the devices were programmed at a base rate of 70 beats/min. In both groups, VP worsened some indexes of left and right ventricular function (P < 0.05) without significantly affecting cardiac output, left ventricular filling pressures and BNP (P = not significant). We conclude that VP should not be considered advantageous compared to slower AF.     

Acute Effects of Multisite Left Ventricular Pacing on Mechanical Dyssynchrony in Patients Receiving Cardiac Resynchronization Therapy

BackgroundA novel quadripolar left ventricular (LV) pacing lead has the ability to deliver multisite LV pacing (MSLV). We set out to characterize the safety and changes in acute mechanical dyssynchrony with MSLV in cardiac resynchronization therapy (CRT) patients.Methods and ResultsProspective multicenter study in 52 patients receiving CRT. An acute pacing protocol comprising 8 MSLV configurations covering a range of delays was compared with conventional CRT (baseline). Transthoracic tissue Doppler imaging (TDI) was used to measure the standard deviation of time to peak contraction of 12 LV segments (Ts-SD) and delayed longitudinal contraction. No ventricular arrhythmia occurred in any of the 52 patients. Complete TDI datasets were collected in 41 patients. Compared with baseline: 1) The mean Ts-SD was significantly lower for the optimal MSLV configuration (35.3 ± 36.4 vs 50.2 ± 29.1 ms; P < .001); 2) at least 1 MSLV configuration exhibited a significant dyssynchrony improvement in 63% of patients; and 3) the mean number of LV segments with delayed longitudinal contractions was significantly reduced with the optimal MSLV configuration (0.37 ± 7.99 vs 2.20 ± 0.19; P < .001).ConclusionsAcute MSLV was acutely safe, and a proportion of MSLV vectors resulted in a significant reduction in echocardiographic dyssynchrony compared with conventional CRT.     

Long-term captopril treatment improves diastolic filling more than systolic performance in rats with large myocardial infarction

Objectives. This study sought determine the effects of long-term angiotensin-converting enzyme (ACE) inhibition on left ventricular (LV) diastolic filling in postinfarction heart failure.Background. Long-term treatment with ACE inhibitors is beneficial in experimental animals and patients with heart failure. Because this treatment typically produces only small improvements in LV systolic function, we hypothesized that improvements in LV diastolic filling might contribute to the overall beneficial effects of ACE inhibitors after myocardial infarction (MI).Methods. We performed transthoracic echocardiographic-Doppler examinations in rats 1 and 6 weeks after transmural MI or sham operation. Rats with MI were randomized to no treatment (n = 10) or captopril (2 g/liter in drinking water, n = 8) after the baseline echocardiogram.Results. Six weeks after MI, untreated rats bad significant LV dilation compared with sham-operated rats (LV diastolic dimension [mean ± SEM] 10.7 ± 0.3 vs. 8.5 ± 0.3 mm, p < 0.05). Rats with untreated MI also had impaired fractional shortening (9 ± 1% vs. 34 ± 2%, p < 0.05) and depressed systolic thickening of the noninfarcted posterior wall (37 ± 3% vs. 65 ± 9%, p < 0.05). Rats with MI showed progressively restricted LV diastolic filling as assessed by transmitral Doppler recordings. At 6 weeks, peak early filling velocity (E) was increased (97 ± 3 vs. 77 ± 2 cm/s, p < 0.05), E wave deceleration was more rapid (23 ± 3 vs. 12 ± 1 m/s², p < 0.05), isovolumetric relaxation time was decreased (18 ± 1 vs. 24 ± 1 ms, p < 0.05), and late filling velocity was lower (26 ± 7 vs. 34 ± 1 cm/s, p < 0.05) in rats with MI versus sham-operated rats. Compared with rats with untreated MI, rats receiving captopril had similar LV diastolic dimensions (10.5 ± 0.35 vs. 10.7 ± 0.35 mm), slightly higher fractional shortening (16 ± 2% vs. 9 ± 1%, p < 0.05 [captopril MI vs. untreated MI]) and unchanged posterior wall thickening (49 ± 12% vs. 37 ± 3%, p = 0.3). In contrast, captopril almost completely normalized diastolic filling abnormalities (E velocity 82 ± 5 cm/s, p < 0.05 [captopril MI vs. untreated MI]; E wave deceleration rate 15 ± 2 m/s², p < 0.05 [captopril MI vs. untreated MI]; isovolumetric relaxation time 20 ± 1 ms).Conclusions. Long-term captopril treatment in rats with a large MI modestly limits LV remodeling and the development of systolic dysfunction but markedly improves the restrictive diastolic filling abnormalities that are seen in untreated rats.     

The impact of age on ablation outcomes in AF-mediated cardiomyopathy

Introduction

The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population.

Objectives

To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF-mediated cardiomyopathy) following CA.

Methods

Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance.

Results

The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p = .686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m² age ≥ 65, p = .834; indexed left ventricular end-diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m² age ≥ 65, p = .681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p = .448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p > .05) albeit a higher CHADS₂VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p < .001).   Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38–1.48, LogRank p = .283) as was AF burden [0% (interquartile range, IQR: 0.0–2.1) vs. age ≥ 65: [0% (IQR 0.0–1.7), p = .516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p = .913), with LV recovery in the vast majority (73% vs. 69%, respectively, p = .759) at 13 (IQR: 12–16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p = .851; 6-min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p = .066), biomarkers (ΔN-terminal-pro brain natriuretic peptide −139 ± 246 vs. −168 ± 181 age ≥ 65,p = .629) and HF symptoms (Short Form-36 survey Δphysical component summary p = .483/Δmental component summary, p = .841).

Conclusion

In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age.     

Altered Early Left Ventricular Diastolic Wall Velocities in Pulmonary Hypertension: A Tissue Doppler Study

Background: Left ventricular diastolic dysfunction (LVDD) is known to occur in severe chronic pulmonary hypertension (PH); however, the mechanism(s) remains unclear. Methods: Tissue Doppler imaging (TDI) was used to track early (E) diastolic signals of basal and mid portions of the interventricular septum (IS) and LV free wall (LVFw) in 20 patients (60 ± 8 years) with documented LVDD without PH and in 30 patients (60 ± 11 years) with known chronic PH. All subjects were in normal sinus rhythm and had normal LV ejection fraction. Results: PH patients had lower early (E) wave velocities in basal IS (–4.2 ± 1.9 vs. –5.9 ± 1.2 cm/sec; P < 0.001), distal IS (–2.6 ± 2.6 vs. –4.2 ± 1.1 cm/sec; P < 0.01), and basal LVFw (–5.2 ± 1.7 vs. –6.5 ± 1.2 cm/sec; P < 0.01) than patients with LVDD and no PH. Finally, worsening PH distorts the entire IS diastolic tracing resulting in asynchronous diastolic signals. Conclusions: The presence of PH not only decreases IS early (E) wave diastolic velocity generation but also distorts the entire pattern of IS diastolic relaxation when compared to patients with typical LVDD and no PH. Further studies are now needed to assess the full effect of PH on LV diastole and how this influences clinical outcomes. (ECHOCARDIOGRAPHY, Volume 26, November 2009)