Electrocardiographic (ECG) clues to differentiate idiopathic right ventricular outflow tract tachycardia (RVOTT) from arrhythmogenic right ventricular cardiomyopathy (ARVC)

Introduction

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetic cardiomyopathy that most commonly affects young adults. The most commonly observed reason of death in patients suffering from ARVC/D is sudden cardiac death (SCD). On the other hand, idiopathic right ventricular outflow tract tachycardia (RVOT VT) usually has a benign course. Both of the entities may have ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern and inferior axis. We tried to propose new discriminating electrocardiographic indices for differentiation of foretold entities.

Material and method

This was a retrospective study. We reviewed records of patients admitted between 2003 and 2012 with the diagnosis of either ARVC/D or RVOT VT that presented with VT (LBBB morphology).

Result

A total of fifty nine patients (30 RVOT VT and 29 ARVC/D) were enrolled. In ARVC/D group, men were dominant while the reverse was true of RVOT VT. Palpitation was more common in the RVOT VT group (90% vs. 66.7%), but aborted SCD and sustained VT were more common in ARVC/D group. The new ECG criteria proposed by us mean QRS duration in V1–V3, QRS difference in right and left precordial leads, S wave upstroke duration, JT interval dispersion, QRS and JT interval of right to left precordial leads were all significantly longer in ARVC/D when compared to RVOT VT patients (p < 0.001).

Conclusion

The proposed ECG criteria can be used for non-invasive diagnosis of ARVC/D and incorporation in the future updates of ARVC/D task force criteria.     

Increase in QRS amplitudes is better than N-terminal pro-B-type natriuretic peptide to predict clinical improvement in decompensated heart failure

Background

We aimed to investigate the correlation between ECG QRS voltage changes, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and clinical improvement in decompensated heart failure (DHF).

Methods and results

DHF patients (n = 56) with a mean age of 67.5 ± 12.6 years showed limb QRS amplitude increase and NT-proBNP level decrease with clinical improvement (p < 0.001). Significant correlation was found between percent changes (Δ%) in body weight and Δ% in QRS voltages of aVR, aVF, DII, ΣQRSI + II and ΣQRS (all limb-leads) (r = − 0.40; r = − 0.35; r = − 0.32; r = − 0.30; r = − 0.30 respectively, p < 0.05). No correlation was found between Δ% in NT-proBNP and body weight (r = − 0.23, p = 0.09). Δ% NT-proBNP was correlated with Δ% QRS voltage only in aVR (r = − 0.312, p = 0.019). In ROC analysis, ≥ 0.5 mm increase in aVR QRS voltage was found to predict ≥ 5 kg weight loss with a sensitivity of 74% and specificity of 62% (p = 0.013, AUC: 0.699).

Conclusions

Increase in QRS voltages especially in aVR was found to be more sensitive than NT-proBNP to predict clinical improvement in DHF.     

Prognostic significance of the absence of normal septal Q waves before aortic valve replacement

Purpose

Aim of this study was to investigate the prognostic significance of absence of septal Q waves in patients scheduled for aortic valve replacement.

Material and Methods

Sixty-one patients who underwent isolated aortic valve replacement for aortic stenosis were retrospectively evaluated. Septal Q waves were defined as Q waves of < 2 mm in amplitude and < 40 ms in width and absence of septal Q waves was defined as simultaneous loss of Q waves from at least three of the leads I, aVL, V5 and V6. Septal Q waves were absent in 17 patients (Group AQ, 27.8%) and were present in 44 patients (Group PQ, 72.1 %) preoperatively. Newly developed AV block > 1st degree and newly developed left bundle branch block were primary endpoints.

Results

Preoperatively, absence of normal septal Q waves was significantly associated with increased risk of postoperative AV block (HR: 11.18, range 1.37–91.21, 95% CI, p = 0.02) whereas it was not associated with increased risk for newly developed LBBB (HR: 3.15 0.62–15.83, 95% CI, p = 0.16).

Conclusion

Absence of normal septal Q waves in the preoperative ECG may predict further delay in conduction which might develop in the early postoperative course of aortic valve replacement.     

A case–control study of non-monitored ECG metrics preceding in-hospital bradyasystolic cardiac arrest: Implication for predictive monitor alarms

Objectives

We investigated whether additional electrocardiographic (ECG) metrics not available on current patient monitors could predict bradyasystolic cardiac arrest in hospitalized adult patients.

Methods

A retrospective case–control design was used to study eight ECG metrics from 22 adult bradyasystolic patients and their 45 control patients. The eight ECG metrics included heart rate, QRS width, interval from P-wave peak to QRS onset (PRp), heart rate-corrected interval from QRS onset to T-wave peak (QTpc), amplitude of QRS peak (rAmp), amplitude of P-wave (pAmp), amplitude of T-wave (tAmp), and absolute difference in the ECG amplitudes at QRS onset and offset divided by rAmp, that is, relative J-point amplitude (relJAmp). We derived the maximal true-positive rate (TPR) of detecting cardiac arrest at a globally minimal false-positive rate (FPR) for each metric and for the absolute slope values resulted from a linear fitting of the time series of these metrics. We also recorded the first time crossing the detection threshold to the time of arrest as lead time.

Results

Conditions of relJAmp > 20% and PRp > 196.6 ms, respectively, achieved a TPR of 22.7% and 27.3% with zero FPRs. The lead prediction time of these two conditions was 5.7 ± 6.8 hours and 8.0 ± 7.2 hours, respectively. Performance of triggers based on the absolute slope values depended on the window length used for linear fitting. rAmp slope of a 2-hour window, PRp slope of a 30-minute window, and relJAmp slope of a 2-hour window achieved the best TPR of 27.3% (FPR = 2.3%, lead time = 6.5 ± 5.7 hours), 14.3% (FPR = 0.0%, lead time = 10.9 ± 10.9), and 18.2% (FPR = 2.3%, lead time = 8.8 ± 9.8), respectively. McNemar test showed that only relJAmp > 20.0% is significantly different from the baseline trigger of HR > 149.3 bpm (p = 0.046). In addition, metrics-based and slope-based triggers were complementary as an “OR” combination of two single-metric triggers raised the TPR up to 45.4% with zero FPR.

Conclusions

It is feasible to compute additional metrics from continuous ECG from bedside monitors. These additional parameters can provide highly specific triggers for predicting bradyasystolic cardiac arrest. Complementary triggers based on the slope of trending of these ECG metrics can further increase the sensitivity without incurring false positives.     

Impact of ostium secundum atrial septal defect closure on the resolution of falsely positive electrocardiographic criteria for myocardial scarring

Background

Electrocardiographic (ECG) Selvester QRS score criteria with false indication of anteroseptal scarring consistent with myocardial infarction have been found in patients with ostium secundum atrial septal defect (OS-ASD). The objective of this study was to evaluate ECGs pre and post percutaneous transcatheter OS-ASD closure to test the hypothesis that the falsely positive criteria for anteroseptal scar decline 1 day post procedure.

Methods

Patients (n = 34, mean age 48 ± 17 years, 79% female) that underwent OS-ASD closure and had undergone pre procedure cardiac magnetic resonance imaging showing no left ventricular (LV) scarring were included in this study. ECGs pre and 1 day post procedure were assessed according to the QRS Selvester scoring system and compared.

Results

Mean Selvester score in anteroseptal regions pre procedure was 6.6 (0.0–6.8) % LV scar and decreased to 4.3 (0.0–6.0) % LV scar one day after the procedure (p = 0.01). Mean Selvester score in lateral regions pre procedure was 3.7 (0.0–3.0) %LV scar and decreased to 2.8 (0.0–0.0) % LV scar one day post procedure (p = 0.25).

Discussion

OS-ASD patients with falsely positive anteroseptal scar criteria by the Selvester QRS score pre procedure have a significant decrease in anteroseptal Selvester score 1 day post procedure. The falsely positive anteroseptal scar criteria did not completely resolve 1 day post procedure. Further studies are needed to investigate the relationship between ECG criteria for anteroseptal scar and right ventricular volume overload in late follow up.     

QRS analysis using wavelet transformation for the prediction of response to cardiac resynchronization therapy: A prospective pilot study

Background

Wider QRS and left bundle branch block morphology are related to response to cardiac resynchronization therapy (CRT). A novel time-frequency analysis of the QRS complex may provide additional information in predicting response to CRT.

Methods

Signal-averaged electrocardiograms were prospectively recorded, before CRT, in orthogonal leads and QRS decomposition in three frequency bands was performed using the Morlet wavelet transformation.

Results

Thirty eight patients (age 65 ± 10 years, 31 males) were studied. CRT responders (n = 28) had wider baseline QRS compared to non-responders and lower QRS energies in all frequency bands. The combination of QRS duration and mean energy in the high frequency band had the best predicting ability (AUC 0.833, 95%CI 0.705-0.962, p = 0.002) followed by the maximum energy in the high frequency band (AUC 0.811, 95%CI 0.663-0.960, p = 0.004).

Conclusions

Wavelet transformation of the QRS complex is useful in predicting response to CRT.     

Evaluation of very low amplitude intra-QRS potentials during the initial minutes of acute transmural myocardial ischemia

Introduction

Low-level electrocardiographic changes from depolarization wavefront may accompany acute myocardial ischemia. The purpose of this study was to assess the changes of microvolt amplitude intra-QRS potentials induced by elective percutaneous coronary interventions (PCI).

Methods

Fifty-seven patients with balloon inflation periods ranging from 3.1 to 7.3 minutes (4.9 ± 0.7 min) were studied. Nine leads continuous high-resolution ECG before and during PCI were recorded and signal-averaged. Abnormal intra-QRS at microvolt level (μAIQP) were obtained using a signal modeling approach. μAIQP, R-wave amplitude and QRS duration were measured in the processed ECG during baseline and PCI episodes.

Results

The mean μAIQP amplitude significantly decreased for each of the standard 12 leads at the PCI event respect to baseline. Left anterior descending artery (LAD) occlusion resulted in a decrease μAIQP in both the precordial leads and the limb leads, while right coronary (RCA) and left circumflex (LCx) arteries occlusions mainly affected limb leads. R-wave amplitude increased during PCI in RCA and LCx groups in lead III but decreased in the precordial leads, while the amplitude decreased in the LAD group in lead III. The average duration of the QRS augmented in groups RCA and LCx but not in the LAD group.

Conclusions

Abnormal intra-QRS potentials at the level of μV provide an excellent tool to characterize the very-low amplitude fragmentation of the QRS complex and its changes due to ischemic injuries. μAIQP shows promise as a new ECG index to measure electrophysiologic changes associated with acute myocardial ischemia.     

Long-term mortality risk in patients with an implantable cardioverter–defibrillator: Influence of heart rate and QRS duration

Background

A paucity of studies has investigated the role of autonomic cardiac regulation as well as cardiac conduction in relation to prognosis in implantable cardioverter–defibrillator (ICD) patients. Therefore, we examined the association of heart rate and QRS duration with long-term mortality risk in first-time ICD patients, adjusting also for measures of emotional distress.

Methods

Resting heart rate and QRS duration were assessed prior to ICD implantation in 448 patients. Primary study endpoint was all-cause mortality (up to 6.0 year follow-up, median follow-up of 5.6 years (IQR: 1.9)). The impact of heart rate and QRS duration on time to all-cause mortality was separately assessed with Cox proportional hazard regression analysis, adjusting for clinical factors and symptoms of depression and anxiety.

Results

Mean (SD) heart rate was 68.0 ± 13.3 bpm and mean QRS duration was 130.9 ± 36.9 ms. Heart rate of ≥ 80 bpm was associated with increased risk of mortality (HR = 1.86; 95% CI = 1.15–3.00; p = .011) in unadjusted analysis. In adjusted analyses, this relationship remained significant both with depression (HR = 1.86, 95% CI = 1.12–3.09; p = .017) and anxiety (HR = 1.82, 95% CI = 1.10–3.03; p = .021) and clinical measures as covariates. QRS duration of ≥ 120 ms was associated with impaired prognosis in unadjusted analysis (HR = 2.00, 95% CI = 1.27–3.14; p = .003), but was reduced to non-significance in adjusted analysis when medical comorbidities were included (HR = 1.15, 95% CI = 0.70–1.89; p = .60).

Conclusions

This study shows that increased heart rate is associated with impaired prognosis. Since heart rate is a relatively easy measurable parameter of autonomic functioning, heart rate should be included as a measure for risk stratification in daily clinical practice.     

The value of the 12-lead ECG for evaluation and optimization of cardiac resynchronization therapy in daily clinical practice

Based on existing literature and some new data we propose a simple three-step strategy using the standard 12-lead ECG for patient selection and optimal delivery of cardiac resynchronization therapy (CRT). (1) Complete LBBB with regard to the indication for CRT can probably best be identified by a QRS duration of ≥ 130 ms for women and ≥ 120 ms for men with the presence of mid-QRS notch-/slurring in ≥ 2 contiguous leads of V₁, V₂, V₅, V₆, I and aVL. (2) Left ventricular (LV) free wall pacing should result in a positive QRS complex in lead V₁, with estimation of the exact LV lead position in the circumferential and apico-basal direction using lead aVF and the precordial leads, respectively. Wide and fractionated LV-paced QRS complexes may indicate pacing in scar tissue. (3) Atrioventricular and interventricular stimulation intervals may be optimized by adjusting them until precordial leads show fusion patterns between left and right ventricular activation wavefronts in the QRS complex.     

Complications in the clinical course of tako-tsubo cardiomyopathy

Objective

This study evaluated the frequency, severity and outcome of complications in the clinical course of tako-tsubo cardiomyopathy (TTC).

Background

TTC is regarded as a benign disease since left ventricular (LV) function returns to normal within a short time. However, severe complications have been reported in selected patients.

Methods

From 37 hospitals, 209 patients (189 female, age 69 ± 12 years) were prospectively included in a TTC registry.

Results

Complications developed in 108/209 patients (52%); 23 (11%) had > 2 complications. Complications occurred median 1 day after symptom onset, and 77% were seen within 3 days. Arrhythmias were documented in 45/209 patients (22%) including atrial fibrillation in 32 (15%) and ventricular tachycardia in 17 (8%). Of 8 patients resuscitated (4%), 6 survived. Additional complications were right ventricular involvement (24%), pulmonary edema (13%), cardiogenic shock (7%), transient intraventricular pressure gradients (5%), LV thrombi (3%) and stroke (1%). During hospitalization, 5/209 patients (2.5%) died. Patients with complications were older (70 ± 13 vs 67 ± 10 years, p = 0.012), had a higher heart rate (91 ± 26 vs 83 ± 19/min, p = 0.025), more frequently Q\ waves on the admission ECG (36% vs 21%, p = 0.019) and a lower LV ejection fraction (47 ± 15 vs 54 ± 14%, p = 0.002). Multivariate regression analysis identified Q-waves on admission (OR 2.49, 95% CI 1.23–5.05, p = 0.021) and ejection fraction ≤ 30% (OR 4.03, 95% CI 1.04–15.67, p = 0.022) as independent predictors for complications.

Conclusions

TTC may be associated with severe complications in half of the patients. Since the majority of complications occur up to day 3, monitoring is advisable for this time period.     

Fragmented QRS complexes are not hallmarks of myocardial injury as detected by cardiac magnetic resonance imaging in patients with acute myocardial infarction

Background

Q waves on a 12-lead electrocardiography (ECG) are considered to be classic hallmarks of prior myocardial infarction. However, one study suggested that the fragmented QRS complex (fQRS) on ECG is a highly sensitive and specific marker of myocardial scarring on a nuclear stress test. The study aimed to investigate the diagnostic accuracy of fragmented QRS complexes compared with Q waves for myocardial injury detected by delayed contrast-enhanced cardiovascular magnetic resonance imaging (DE-CMRI) in subjects with acute myocardial infarction.

Methods

Electrocardiograms of 190 subjects with myocardial infarction who underwent DE-CMR were analyzed. fQRS was defined by the presence of an additional R wave (R″), or notching of the S wave, or more than one R′ in two contiguous leads.

Results

Delayed enhancement was observed in 180 (94.7%) patients. Transmural enhancement was noted in 78 (43.3%) and subendocardial enhancement in 102 (56.7%) patients. The sensitivity and specificity of Q waved and fQRS for diagnosing delayed enhancement were 59.4% vs. 66.7% and 90.0% vs. 40.0%. The area under the receiver–operator characteristics curve of delayed enhancement was 0.75 for Q waves and 0.53 for fQRS (p = 0.04). The areas under the ROC curves of the transmurality of delayed enhancement were 0.44 for fQRS and 0.58 for Q waves (p = 0.73).

Conclusions

fQRS has poor accuracy for the detection of myocardial injury compared with Q waves. fQRS and Q waves are not valuable tools for the diagnosis transmural irreversible myocardial injury in acute myocardial infarction.     

Underestimation of duration of ventricular activation by 12-lead ECG compared with direct measurement of activation duration derived from implanted pacemaker leads

Aim

To determine extent to which 12-lead ECG QRS duration (QRSd) reflects ventricular activation duration compared with time relations from unpaced ventricular myograms in cardiac resynchronisation therapy (CRT) patients.

Methods

Left (LV) and right ventricular (RV) myograms were recorded during spontaneous rhythm from in-situ pacemaker leads in 77 patients receiving CRT; 14 ‘normal activation’ (unpaced QRSd < 120 ms), 10 ‘simple left bundle branch block’ (LBBB, QRSd 120-149 ms), 40 ‘advanced LBBB’ (QRS ≥ 150 ms) and 13 right bundle branch block. Delay in onset (Q-LV, Q-RV) and duration (dur-LV, dur-RV) of activation were measured. Interventricular delay (ΔT: Q-LV minus Q-RV) and ‘LV-overrun’ (time between end 12-lead QRS and Q-end LV myogram) were calculated.

Results

‘Normal activation’: Neither Q-LV, Q-RV (38 ± 6 ms, 39 ± 11 ms), nor dur-LV, dur-RV (66 ± 9 ms, 81 ± 25 ms) differed. ΔT (− 1 ± 11 ms) was not different from zero, nor was Q-end LV (104 ± 10 ms) different from QRSd (p = 0.09).‘Simple LBBB’: Q-LV (102 ± 28 ms) was longer than ‘normal activation’ (p < 0.001), but Q-RV, dur-LV, and dur-RV were no different. ΔT (54 ± 23 ms) was increased (p < 0.001) and Q-end LV (187 ± 48 ms) was longer than QRSd (p = 0.005).‘Advanced LBBB’: Q-LV (115 ± 52 ms) was longer than ‘normal activation’ (p < 0.001) but Q-RV was no different, so ΔT (72 ± 47 ms) was increased (p < 0.001 compared to normal, p = 0.04 compared to simple LBBB). Dur-LV (102 ± 27 ms) was also prolonged, so Q-end LV (218 ± 48 ms) was longer than QRSd (p < 0.001). Longer LV-overrun was associated with longer ΔT (p < 0.001).

Conclusions

Prolonged LV myopotential duration, associated with interventricular delay, is electrically silent on 12-lead QRSd. Unpaced surface QRSd underestimates true duration of native LV activation in CRT patients.     

A reduction in total isovolumic time with cardiac resynchronisation therapy is a predictor of clinical outcomes

Background

Total isovolumic time (t-IVT) reflects left ventricular (LV) asynchrony (when the ventricle is neither ejecting nor filling). It is prolonged in left bundle branch block (LBBB). Cardiac resynchronisation therapy (CRT) is a treatment for patients with heart failure, reduced LV ejection fraction and LBBB. CRT shortens t-IVT, but the long-term clinical benefit of such reduction after CRT has not been studied in this patient group.

Methods

Seventy-three patients who underwent CRT had t-IVT measured before and after CRT implantation. The study end-point was a composite of unplanned heart failure hospitalisation and all-cause mortality.

Results

Baseline t-IVT showed considerable scatter: 30 patients had t-IVT values longer than 15 s/min (upper 95% limit of normal). The change in t-IVT with CRT was also variable: t-IVT shortened in 50 patients (from 16.2 ± 4.8 s/min to 11.7 ± 3.7 s/min: group A), and lengthened in 23 patients (from 11.7 ± 4.2 s/min to 14.5 ± 4.33 s/min: group B). The magnitude of change in t-IVT with CRT negatively correlated with baseline t-IVT (r = − 0.619, p < 0.001); thus t-IVT (significantly longer in group A than group B before CRT: 16.2 ± 4.8 s/min vs. 11.7 ± 4.2 s/min, p < 0.001) became significantly shorter in group A compared to group B after CRT (11.7 ± 3.7 s/min vs. 14.5 ± 4.3 s/min, p = 0.005). After follow-up of 30 months, 70% group A patients had event-free survival compared to 39% group B patients. The presence of any fall in t-IVT after CRT was an independent predictor of event-free survival.

Conclusion

T-IVT is a marker of global cardiac asynchrony that has predictive capacity on functional, symptomatic, and mortality endpoints in patients with advanced heart failure.     

Cardiovascular magnetic resonance imaging in asymptomatic patients with connective tissue disease and recent onset left bundle branch block

Background–aim

Recent LBBB in connective tissue diseases (CTDs) is challenging, due to high incidence of underlying pathology that may remain undetected, due to limitations of imaging tests. We hypothesized that cardiovascular magnetic resonance (CMR) may be of diagnostic value in CTDs with recent LBBB and normal echocardiogram.

Patients–methods

26 CTDs, aged 32 ± 7 yrs (19 F) and 26 controls without CTDs, aged 60 ± 4 yrs (10 F) with recent LBBB and normal echo were evaluated by CMR. The CTDs included 6 sarcoidosis (SRC), 4 systemic sclerosis (SSc), 6 systemic lupus erythematosus (SLE), 6 rheumatoid arthritis (RA) and 4 inflammatory myopathies (IM). CMR was performed by 1.5 T. LVEF, T2 ratio (oedema imaging) and late gadolinium enhancement (LGE) (fibrosis imaging) were evaluated. Acute and chronic lesions were characterised by T2 > 2 and positive LGE and T2 < 2 and positive LGE, respectively. According to LGE, lesions were characterised as diffuse subendo-, subepicardial/intramural not following and subendocardial/transmural following the distribution of coronaries, indicative of vasculitis, myocarditis and myocardial infarction, respectively.

Results

CTDs were younger (p < 0.001), with higher incidence of abnormal CMR (42.31 vs 30.77%, p = NS), including dilated cardiomyopathy (11.54%), diffuse subendocardial fibrosis (11.54%), myocardial infarction (7.69%) and acute myocarditis (11.54%) vs dilated cardiomyopathy (19.23%), myocardial infarction (7.69%) and acute myocarditis (3.85%), detected in non-CTDs.

Conclusions

In CTDs with recent LBBB, CMR documented acute and chronic cardiac pathology, particularly myocarditis. CMR should be considered as an adjunct to conventional diagnostic workup in both patient groups, more so in CTDs.     

ABCC9 is a novel Brugada and early repolarization syndrome susceptibility gene

Background

Genetic defects in KCNJ8, encoding the Kir6.1 subunit of the ATP-sensitive K⁺ channel (I_K-ATP), have previously been associated with early repolarization (ERS) and Brugada (BrS) syndromes. Here we test the hypothesis that genetic variants in ABCC9, encoding the ATP-binding cassette transporter of I_K-ATP (SUR2A), are also associated with both BrS and ERS.

Methods and results

Direct sequencing of all ERS/BrS susceptibility genes was performed on 150 probands and family members. Whole-cell and inside-out patch-clamp methods were used to characterize mutant channels expressed in TSA201-cells. Eight ABCC9 mutations were uncovered in 11 male BrS probands. Four probands, diagnosed with ERS, carried a highly-conserved mutation, V734I-ABCC9. Functional expression of the V734I variant yielded a Mg-ATP IC₅₀ that was 5-fold that of wild-type (WT). An 18-y/o male with global ERS inherited an SCN5A-E1784K mutation from his mother, who displayed long QT intervals, and S1402C-ABCC9 mutation from his father, who displayed an ER pattern. ABCC9-S1402C likewise caused a gain of function of I_K-ATP with a shift of ATP IC₅₀ from 8.5 ± 2 mM to 13.4 ± 5 μM (p < 0.05). The SCN5A mutation reduced peak I_Na to 39% of WT (p < 0.01), shifted steady-state inactivation by − 18.0 mV (p < 0.01) and increased late I_Na from 0.14% to 2.01% of peak I_Na (p < 0.01).

Conclusion

Our study is the first to identify ABCC9 as a susceptibility gene for ERS and BrS. Our findings also suggest that a gain-of-function in I_K-ATP when coupled with a loss-of-function in SCN5A may underlie type 3 ERS, which is associated with a severe arrhythmic phenotype.     

Right atrial area and right ventricular outflow tract akinetic length predict sustained tachyarrhythmia in repaired tetralogy of Fallot

Aims

Repaired tetralogy of Fallot (rtoF) patients are at risk of atrial or ventricular tachyarrhythmia and sudden cardiac death. Risk stratification for arrhythmia remains difficult.We investigated whether cardiac anatomy and function predict arrhythmia.

Methods

One-hundred-and-fifty-four adults with rtoF, median age 30.8 (21.9–40.2) years, were studied with a standardised protocol including cardiovascular magnetic resonance (CMR) and prospectively followed up over median 5.6 (4.6–7.0) years for the pre-specified endpoints of new-onset atrial or ventricular tachyarrhythmia (sustained ventricular tachycardia/ventricular fibrillation).

Results

Atrial tachyarrhythmia (n = 11) was predicted by maximal right atrial area indexed to body surface area (RAAi) on four-chamber cine-CMR (Hazard ratio 1.17, 95% Confidence Interval 1.07–1.28 per cm²/m²; p = 0.0005, survival receiver operating curve; ROC analysis, area under curve; AUC 0.74 [0.66–0.81]; cut-off value 16 cm²/m²). Atrial arrhythmia-free survival was reduced in patients with RAAi ≥ 16 cm²/m² (logrank p = 0.0001). Right ventricular (RV) restrictive physiology on echocardiography (n = 38) related to higher RAAi (p = 0.02) and had similar RV dilatation compared with remaining patients.Ventricular arrhythmia (n = 9) was predicted by CMR RV outflow tract (RVOT) akinetic area length (Hazard ratio 1.05, 95% Confidence Interval 1.01–1.09 per mm; p = 0.003, survival ROC analysis, AUC 0.77 [0.83–0.61]; cut-off value 30 mm) and decreased RV ejection fraction (Hazard ratio 0.93, 95% Confidence Interval 0.87–0.99 per %; p = 0.03). Ventricular arrhythmia-free survival was reduced in patients with RVOT akinetic region length > 30 mm (logrank p = 0.02).

Conclusion

RAAi predicts atrial arrhythmia and RVOT akinetic region length predicts ventricular arrhythmia in late follow-up of rtoF. These are simple, feasible measurements for inclusion in serial surveillance and risk stratification of rtoF patients.     

Serum osteoprotegerin and osteopontin levels are associated with arterial stiffness and the presence and severity of coronary artery disease

Background

Osteopontin (OPN) and osteoprotegerin (OPG) have recently emerged as key factors in both vascular remodeling and development of atherosclerosis. Arterial stiffness has an independent predictive value for cardiovascular events. We evaluate the relationship between OPG, OPN serum levels and vascular function in coronary artery disease (CAD) patients.

Methods

The study population was consisted of 409 subjects (280 with CAD and 129 without CAD). Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. OPG and OPN levels were measured, as markers of vascular remodeling and calcification, by ELISA. Gensini score was used to evaluate the extent of CAD.

Results

CAD patients, compared to those without CAD, had higher OPG (3.91 ± 1.87 pmol/l vs. 2.88 ± 1.32 pmol/l, p < 0.001) and logOPN levels (1.81 ± 0.18 ng/ml vs. 1.71 ± 0.24 ng/ml, p < 0.001) and impaired PWV (8.94 ± 2.21 m/s vs. 8.28 ± 1.91 m/s, p = 0.006). Furthermore, PWV was associated with serum OPG levels (r = 0.19, p < 0.001) and with serum logOPN levels (r = 0.10, p = 0.049). Multivariate linear regression analysis revealed that increased OPG (p = 0.013) and logOPN (p = 0.006) levels are associated with 3‐vessel CAD and Gensini score (p = 0.04 for OPG and p = 0.09 for OPN), independently of other known cardiovascular risk factors.

Conclusion

The present study revealed that serum OPG and OPN levels are positively associated with arterial stiffness, and with the extent of CAD. These preliminary results suggest that OPG and OPN levels are significantly correlated with vascular function contributing to the pathogenesis of atherosclerosis in CAD. Further studies are needed to explore the mechanisms of action of OPG and OPN in CAD.     

Sex-Specific Mortality Risk by QRS Morphology and Duration in Patients Receiving CRT : Results From the NCDR

Background

Prior studies have suggested that women have better outcomes than men after cardiac resynchronization therapy-defibrillator (CRT-D) implantation.

Objectives

The purpose of this study was to compare mortality after CRT-D implantation by sex, QRS morphology, and duration.

Methods

Survival curves and covariate adjusted hazard ratios (HR) were used to assess mortality by sex in 31,892 CRT-D patients in the National Cardiovascular Data Registry (NCDR), implantable cardioverter defibrillator (ICD) registry between 2006 and 2009, with up to 5 years’ follow-up (median 2.9 years, interquartile range: 2.0 to 3.9 years). Patients were grouped by QRS morphology and 10-ms increments in QRS duration.

Results

Among patients with left bundle branch block (LBBB), women had a 21% lower mortality risk than men (HR: 0.79; 95% CI: 0.74 to 0.84; p < 0.001); however, there was no sex difference in non-LBBB (HR: 0.95; 95% CI: 0.85 to 1.06; p = 0.37). Longer QRS duration was associated with better survival in both sexes with LBBB, but not in patients without LBBB. Compared with women with LBBB and QRS of 120 to 129 ms, women with LBBB and QRS of 140 to 149 ms had a 27% lower mortality (HR: 0.73; 95% CI: 0.60 to 0.88; p = 0.001); this difference was 18% in men (HR: 0.82; 95% CI: 0.71 to 0.93; p = 0.003). Mortality in LBBB and QRS of 150 ms or longer compared with those with LBBB and QRS of 120 to 129 ms was similar between sexes (HR: 0.61 to 0.68; p < 0.001 for women and HR: 0.58 to 0.66; p < 0.001 for men). Sex interactions within 10-ms groups were not significant.

Conclusions

Among patients with LBBB who received CRT-D, mortality is lower in women than men. Additionally, longer QRS duration in LBBB is associated with better survival in both sexes. In contrast, there is no sex difference in patients without LBBB, regardless of QRS duration. Further studies should include a non-CRT comparator group to confirm these findings.     

Determinants and clinical significance of flow via the fenestration in the Fontan pathway: A multimodality study

Background

The use of a fenestration in the Fontan pathway remains controversial, partly because its hemodynamic effects and clinical consequences are insufficiently understood. The objective of this study was to quantify the magnitude of fenestration flow and to characterize its hemodynamic consequences after an intermediate interval after surgery.

Methods

Twenty three patients with a fenestrated extracardiac conduit prospectively underwent investigation by cardiac magnetic resonance (CMR), echocardiography, and invasive manometry under the same general anesthetic 12 ± 4 months after Fontan surgery. Fenestration flow was determined using phase contrast CMR by subtracting flow in the Fontan pathway above the fenestration from Fontan flow below the fenestration.

Results

Fenestration flow constituted a mean of 31 ± 12% (range 8–50%) of ventricular preload. It was associated with a lower Qp/Qs (r = − 0.64, p = 0.001) and oxygen saturation (r = − 0.74, p < 0.0001). Fenestration flow volume was correlated with pulmonary vascular resistance (r = 0.45, p = 0.04) and markers of ventricular diastolic function (early diastolic strain rate r = 0.57, p = 0.008 and ventricular untwist rate r = 0.54, p = 0.02).In 14 patients (61%) all of the net inferior vena cava flow and part of the superior vena cava flow were diverted into the systemic atrium and did not reach the lungs.

Conclusions

Fenestration flow can be measured accurately with CMR. In two-thirds of the patients not only all of the inferior vena cava flow, but also some of the superior vena cava flow is diverted through the fenestration. Fenestration flow is driven by a balance between pulmonary vascular resistance and early diastolic ventricular function.     

左束支阻滞型特发性室性心动过速的心电图特征对射频消融成功的影响初探

对心电图呈左束支阻滞型的特发性室性心动过速 (简称室速 )的临床特点和心电图进行分析 ,以了解哪些因素可以预测此类患者从右室流出道行射频消融的成功率。对 2 6例特发性室速的患者进行电生理检查和射频消融手术 ,全部患者室速时的心电图呈左束支阻滞。结果 :2 6例中 ,2 2例于右室流出道进行了成功消融 ,成功和未成功消融的患者临床特征和电生理无明显区别 ,成功消融的患者中胸前V1 导联心电图呈rS型 (1 2例 )和QS型 (1 0例 ) ,而 4例未成功者 ,V1 导联均呈rS型 ,其中 2例经主动脉于左冠状窦消融成功。在成功与未成功消融患者中 ,V1 导联有无R波无明显区别 ,但V1 导联无R波预示室速可以从右室流出道成功消融 ,成功消融的室速患者胸前导联的平均移行区在V4导联 ,而未成功患者胸前导联的移行区在V3 或V2 导联。结论 :某些心电图呈左束支阻滞 ,且额面电轴正常或右偏的特发性室速患者不能成功从右室流出道消融 ,V1 导联有r波且移行区在V3 导联或之前者提示此类心电图特征的室速可能非起源于右室流出道 ,部分可能起源于左室流出道