Elena Efimova

Left ventricular function improvement after prophylactic implantable cardioverter-defibrillator implantation in patients with non-ischaemic dilated cardiomyopathy

AIMS To assess the incidence and prognostic significance of left ventricular (LV) function improvement in patients with non-ischaemic dilated cardiomyopathy (DCM) and prophylactic implantable cardioverter-defibrillator (ICD). METHODS AND RESULTS A total of 123 patients with DCM and echocardiographic follow-up assessments within 1 year after prophylactic ICD implant were retrospectively studied at our institution. All patients had New York Heart Association class II or III symptoms in the presence of a LV ejection fraction of 23 ± 6% (range: 9-35%) despite optimized medical therapy for at least 3 months prior to ICD implant. Left ventricular function improvement was defined as an increase of LV ejection fraction of more than 5% to more than 35% combined with a decrease LV end-diastolic diameter of at least 5 mm. Left ventricular function improvement after prophylactic ICD implant was found in 30 of 123 patients (24%). Multivariate logistic regression revealed recent onset DCM with symptoms ≤9 months as the only significant predictor of LV function improvement [odds ratio: 6.89; 95% confidence interval (CI): 2.43-21.99, P = 0.0002]. During 74 months mean follow-up, total mortality was higher in patients without vs. with LV function improvement [hazard ratio (HR): 3.75; 95% CI: 1.14-12.31, P = 0.0034], while the incidence of appropriate ICD therapies was similar in both groups in the early phase after prophylactic ICD implant (HR: 1.15; 95% CI: 0.57-2.33, P = 0.70). The incidence of appropriate ICD therapies decreased to ∼1% per year after LV function improvement had occurred. CONCLUSION Recently diagnosed DCM predicts LV function improvement after prophylactic ICD implant. Overall survival was significantly better in patients with vs. without LV function improvement, while appropriate ICD therapy rates were similar in both groups in the early phase after prophylactic ICD implantation before LV function improvement occurred.

Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach

BACKGROUND Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG. OBJECTIVE The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study. METHODS We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19). RESULTS Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin. CONCLUSION A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.

Predictors of ventricular arrhythmia after left ventricular assist device implantation: A large single-center observational study

BACKGROUND Ventricular arrhythmias (VAs) are common in patients after left ventricular assist device (LVAD) implantation. OBJECTIVE The purpose of this study was to determine the predictors of VAs and their impact on mortality in LVAD patients. METHODS A total of 98 consecutive patients with an implantable cardioverter-defibrillator (ICD) (86 [88%] male, mean age 57 ± 10 years), 57 [58%] with nonischemic dilated cardiomyopathy) who had received an LVAD between May 2011 and December 2013 at our institution were included in the study. RESULTS Mean left ventricular ejection fraction and left ventricular end-diastolic diameter were 20% ± 8% and 73 ± 11 mm, respectively. Seventy-three patients (75%) had atrial fibrillation (AF). During the 12 months before LVAD implantation, 38 patients (39%) had experienced ≥1 episode of VAs (11.5 ± 20) requiring ICD therapies. The number of patients with VAs was comparable among all types of ICDs (P = .48). During the 12-month follow-up after LVAD implantation, 48 patients (49%) experienced ≥1 episode of VAs (30 ± 98) with appropriate ICD therapies. The prevalence of VAs was significantly higher among patients with pre-LVAD VAs compared to those without VAs during the year before LVAD implantation (66% vs 38%; P = .008). In a binary multiple logistic regression analysis, pre-LVAD VAs (hazard ratio 5.36, 95% confidence interval 2.0-14.3; P = .001) and AF (hazard ratio 3.1, 95% confidence interval 1.1-11.9; P = .024) predicted post-LVAD VAs. CONCLUSION Pre-LVAD VAs and AF predict the occurrence of VAs after LVAD implantation. According to the latest data on the negative impact of post-LVAD VAs on all-cause mortality, further studies should clarify the reasonability of maintaining sinus rhythm in patients with AF and/or prophylactic catheter ablation of ventricular tachycardias before LVAD implantation.

Adenosine sensitivity of retrograde fast pathway conduction in patients with slow-fast atrioventricular nodal reentrant tachycardia: A prospective study

BACKGROUND It is suggested that the adenosine resistance of retrograde fast pathway in slow-fast atrioventricular nodal reentrant tachycardia (AVNRT) confirms the participation of a concealed retrograde atrio-Hisian pathway rather than the conventional fast pathway in the arrhythmia circuit of slow-fast AVNRT. OBJECTIVE To prospectively assess the retrograde fast pathway response to the intravenous administration of adenosine in patients with typical AVNRT and the control group. METHODS Electrophysiological parameters and adenosine sensitivity of retrograde fast pathway were studied in 21 consecutive patients (18 women; mean age 57 ± 10 years) with slow-fast AVNRT and 24 patients (11 women; mean age 46 ± 16 years) as the control group. RESULTS Fifteen (71%) patients with AVNRT and 18 (75%) patients in the control group developed transient ventriculoatrial (VA) block after the intravenous administration of adenosine (P = .79). In patients with slow-fast AVNRT, female sex (P = .003), longer VA interval during right ventricular pacing (P < .001), and longer tachycardia cycle length (P < .001) predicted transient VA block after the intravenous administration of adenosine. In patients in the control group, a shorter VA interval during fixed rate right ventricular apical pacing (P = .009) and the presence of dual atrioventricular nodal physiology (P = .002) were associated with the adenosine resistance of the retrograde fast pathway. CONCLUSIONS The prevalence of the adenosine resistance of retrograde fast pathways conduction is comparable between patients with and those without slow-fast AVNRT. This finding can be explained better by the existence of an insulated intranodal tract with Purkinje-like properties or a superior atrionodal connection to the nodo-Hisian region of the atrioventricular node rather than the presence of an atrio-Hisian pathway.

Reversibility of severe mitral valve regurgitation after left ventricular assist device implantation: single-centre observations from a real-life population of patients

OBJECTIVES This study evaluates the impact of untreated preoperative severe mitral valve regurgitation (MR) on outcomes after left ventricular assist device (LVAD) implantation. METHODS Of the 234 patients who received LVAD therapy in our centre during a 6-year period, we selected those who had echocardiographic images of good quality and excluded those who underwent mitral valve replacement prior to or mitral valve repair during LVAD placement. The 128 patients selected were divided into 2 groups: Group A with severe MR (n = 65) and Group B with none to moderate MR (n = 63, 28 with moderate MR). We evaluated transthoracic echocardiography preoperatively [15 (7-28) days before LVAD implantation; median (interquartile range)] and postoperatively up to the last available follow-up [501 (283-848) days after LVAD]. We collected mortality, complications and clinical status indicators of the patient cohort. RESULTS We observed a significant decrease in the severity of MR after LVAD implantation (severe MR 51% pre- vs 6% post-LVAD implantation, P < 0.001). There was no difference between groups in terms of right heart failure, rate of urgent heart transplantation, pump thrombosis or ventricular arrhythmias. There was no difference in 1-year survival and 3-year survival (87.7% vs 88.4% and 71.8% vs 66.6% for Groups A and B, respectively, P = 0.97). CONCLUSIONS Preoperative severe MR resolves in the majority of patients early on after LVAD implantation and is not associated with worse clinical outcomes or intermediate-term survival.

Supraventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy associate with long-term outcome after catheter ablation of ventricular tachycardias

Aims This study aimed to assess the impact of supraventricular tachycardia (SVT) on long-term results of radiofrequency catheter ablation therapy of ventricular tachycardia (VT) in a large cohort of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Methods and results Supraventricular tachycardia occurrence has been studied in patients from our ARVD/C registry (70 patients, 48 male, age 53.2 ± 14.0, 45 patients (64.3%) with previous VT ablation). SVT were diagnosed in 26 of 70 patients (37.1%). Atrial fibrillation (AF) was the most frequent atrial arrhythmia, diagnosed in 17 patients (24.3%). In univariate analysis advanced age, clinical symptoms of heart failure, enlarged right atrium, diagnosis of significant tricuspid regurgitation (TR), and inappropriate implantable cardioverters-defibrillators therapy were associated with SVT. In binary logistic regression analysis only heart failure: hazard ratio (HR) 10.89, 95% confidence interval (95% CI) 1.08-109.96 (P = 0.043) and significant TR: HR 4.79, 95% CI 1.35-16.33 (P = 0.015) remained associated with SVT. In patients with previous VT ablation Cox multiple regression survival analysis revealed older age (≥53 years): HR 4.63, 95% CI 1.51-14.24 (P = 0.008) and SVT: HR 3.01, 95% CI 1.15-7.89 (P = 0.025) as predictors for VT recurrence during the follow-up. Conclusion SVT and older age are associated with the recurrence of VT after catheter ablation in patients with ARVD/C.