Hanno Oswald

Efficacy of pulmonary vein isolation by cryoballoon ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND Radiofrequency ablation of pulmonary veins (PVs) has emerged as an effective treatment for patients with paroxysmal atrial fibrillation (AF). However, serious complications raise concern about an even wider application. In terms of safety, cryoenergy has advantages compared with radiofrequency. A new cryoenergy balloon catheter has been recently developed to make AF ablation shorter and safer. OBJECTIVE The purpose of this study was to test the 6-month efficacy of this new device for ablation of paroxysmal AF. METHODS Twenty-one patients with highly symptomatic paroxysmal AF, normal left atrial size, and frequent episodes of AF were included. All PVs were targeted during cryoballoon ablation. Patients received 24-hour Holter electrocardiograms (ECGs) and event recorder during follow-up after 1, 3, and 6 months. RESULTS A total of 81 (95%) of 85 PVs could be completely isolated with a single-balloon technique. Procedure time was 165 +/- 35 minutes, and fluoroscopy time was 39 +/- 9 minutes. After 6 months, 86% of the patients were free of symptomatic AF. In two of three patients with recurrence of AF, complete PV isolation has not been achieved initially. After a second procedure (1.04 procedures per patient), 90% of the patients were free of symptomatic AF. Three phrenic nerve palsies occurred during ablation of the right superior PV; two completely resolved after 6 and 9 months, and one is still persisting after 2 months. CONCLUSION This is the first study that reports the results of the new cryoballoon AF ablation approach showing 86% freedom from AF recurrence after 6 months. Cryoballoon PV ablation promises to be effective for patients with paroxysmal AF and normally sized left atria.

Implantable defibrillator therapy for ventricular tachyarrhythmia in left ventricular assist device patients

Ventricular arrhythmias (VA) occur frequently after permanent left ventricular assist device (LVAD) implantation in end stage heart failure. Left ventricular assist device patients require rhythm control in contrast to patients with biventricular support. However, the rationale for implantable cardioverter‐defibrillator (ICD) utilization in LVAD patients remains unclear. This study investigated the safety and efficacy of primary prevention ICD therapy and the rate of appropriate ICD interventions in LVAD patients.

Risk for ventricular fibrillation in peripartum cardiomyopathy with severely reduced left ventricular function—value of the wearable cardioverter/defibrillator

The true incidence of life‐threatening ventricular tachyarrhythmic events and the risk of sudden cardiac death in the early stage of peripartum cardiomyopathy (PPCM) are still unknown. We aimed to assess the usefulness of the wearable cardioverter/defibrillator (WCD) to bridge a potential risk for life‐threatening arrhythmic events in patients with early PPCM, severely reduced left ventricular ejection fraction (LVEF) and symptoms of heart failure.

Implantable defibrillator with left ventricular assist device compatibility

Implanted defibrillator (ICD) and HeartMate-II (Thoratec, Pleasanton, CA, USA) left ventricular assist device (LVAD) incompatibilities have been reported. In order to show which ICD would function regularly in Heart Mate II recipients, we conducted a systematic review of 39 consecutive patients with implanted ICD and HeartMate-II from our institutions LVAD registry. Forty-six ICDs were identified without device interactions in most ICD devices. However, loss of ICD to programmer telemetry was observed in four patients with V-193, V-196 and V-350 (St Jude Medical, Sunnyvale, CA, USA) and one patient with an Ovatio DR (Sorin, Milan, Italy) requiring ICD replacement. The majority of all investigated ICDs operated without LVAD to ICD interaction. However, surgeons implanting the Heart Mate II in ICD patients should be aware of possible interactions and incompatible devices should not be recommended in HeartMate-II recipients.

Right ventricular pacing is an independent predictor for ventricular tachycardia/ventricular fibrillation occurrence and heart failure events in patients with an implantable cardioverter-defibrillator.

AIMS There is increasing evidence that right ventricular (RV) pacing may have detrimental effects by increasing morbidity and mortality for heart failure in implantable cardioverter-defibrillator (ICD) patients. In this study we prospectively tested the hypothesis that cumulative RV pacing increases ventricular tachycardia/ventricular fibrillation (VT/VF) occurrence (primary endpoint) and hospitalization and mortality for heart failure (secondary endpoint) in a predominantly secondary prophylactic ICD patient population. METHODS AND RESULTS Two hundred and fifty patients were divided into two groups according to the median of cumulative RV pacing (< or =2 vs. >2%) and prospectively followed-up for occurrence of primary and secondary endpoints for 18 +/- 4 months. Established predictors for VT/VF occurrence and heart failure events such as age, left ventricular ejection fraction (EF), QRS duration, history of atrial fibrillation, and NT-proBNP were collected at enrollment. Multivariate Cox regression analysis revealed that cumulative RV pacing > 2% and EF < 40% were independent predictors for VT/VF occurrence and heart failure events. Kaplan-Meier analysis showed that patients with >2% cumulative RV pacing more frequently suffered from VT/VF occurrence and heart failure hospitalization. CONCLUSION Cumulative RV pacing > 2% and EF < 40% are independent predictors for VT/VF occurrence and mortality and hospitalization for heart failure in predominantly secondary prophylactic ICD patients. Our data show that algorithms capable of reducing cumulative RV pacing should be used more frequently in clinical practice.

Difference in humoral biomarkers for myocardial injury and inflammation in radiofrequency ablation versus cryoablation.

Background: Markers of myocardial injury and inflammation have been shown to be elevated following radiofrequency (RF) ablation. This study aimed to compare RF ablation and cryoablation for their impact on markers for myocardial injury and inflammation.

Effect of Restoring Sinus Rhythm on Sleep Apnea in Patients With Atrial Fibrillation or Flutter

Sleep apnea (SA) is more prevalent in patients with atrial fibrillation (AF), but the impact of cardioversion on disordered breathing is unknown. Thus, we investigated the influence of restoring sinus rhythm in patients with AF and atrial flutter (AFlut) on SA. The 16 patients (mean age 63.1 +/- 11.2) with AF (n = 6) or AFlut (n = 10) and SA (apnea-hypopnea index >10) received cardioversion or ablation of cavotricuspid isthmus. We compared the severity of SA by sleep polygraphy under AF/Aflut with the first night after restoring sinus rhythm and after 4 weeks. Apnea-hypopnea index before and immediately after restoring sinus rhythm was similar (31.7 +/- 13.2 vs 30.1 +/- 15.7, p = NS) despite a significantly reduced heart rate (86.7 +/- 26.5 vs 67.8 +/- 11.9 beats/min, p <0.02). After 4 weeks, apnea-hypopnea index remained unchanged (38.1 +/- 18.1, p = NS) although heart rate was further reduced (61.8 +/- 8.8 beats/min, p <0.003). In our study, SA could not be improved by cardioversion of AF/AFlut. Therefore, although it is well known that SA leads to AF, eliminating AF does not cure or improve SA. In conclusion, our study shows that AF should be regarded more as an innocent bystander than a causative or aggravating condition in SA.

Treatment of patients with recurrent or persistent infection of cardiac implantable electronic devices.

BACKGROUND Increasing rates of bacterial infections in device therapy of cardiac rhythm disturbances pose a clinical problem. Radical surgical treatment yields the best long-term results but is frequently preceded by conservative treatment or limited surgical procedures leading to an unnecessary long treatment course. Recurrence/persistence of infection then potentially poses an even more serious clinical problem. METHODS AND RESULTS A total of 192 consecutive explantation procedures were performed for cardiac implantable electronic device (CIED) infections over a 10 year period. Forty-nine cases followed recurrence of infection subsequent to prior surgical treatment for device infection. Differences in patient/disease characteristics and outcome were looked for in recurrent as compared to primary infections (referral mode) to identify a potential requirement for adjusting treatment in recurrence. With a minimum follow-up of 24 months, 98% eradication of infection was observed independent of referral mode. Differences between primary and recurrent infection essentially reflected the primary presenting clinical picture-chronic smouldering vs. acute systemic infection. Various parameters that follow from this differentiation are significantly different between the groups. There was however no difference in outcome in terms of mortality and rate of recurrence. In addition, the parameters of the extraction procedure did not differ considerably. CONCLUSION Despite significant differences in baseline and disease characteristics between primary and recurrent CIED infection, a standardized radical protocol results in an equally high success rate in eradicating infection in both groups. Nevertheless, direct and un-delayed referral of patients with suspected CIED infection to specialized centres is recommended as it saves time for the patient.

Clinical relevance of slow ventricular tachycardia in heart failure patients with primary prophylactic implantable cardioverter defibrillator indication

AIMS Implantable cardioverter defibrillators (ICDs) have shown to reduce all-cause mortality in heart failure patients. In SCD-HeFT study, ICDs were programmed with a detection zone of ≥ 187 b.p.m. Thus, the incidence and clinical significance of slower ventricular tachycardias (VTs) in these patients remains largely unknown, though clinically important for device selection, programming, and follow-up. METHODS AND RESULTS We prospectively studied symptomatic heart failure patients with an indication for a primary prophylactic ICD with or without concomitant resynchronization therapy according to SCD-HeFT inclusion criteria. Devices were programmed to an additional monitor zone for slow VTs at heart rates 130-186 b.p.m. Two hundred consecutive patients (86% male) were followed for a mean of 509 ± 308 days. One hundred and thirty-seven patients (68.5%) were New York Heart Association class III, 75 patients (37.5%) were on cardiac resynchronization therapy, and 124 (62%) had ischaemic cardiomyopathy. We observed 473 VT episodes in 36 patients (18%) and 131 ventricular fibrillation episodes in 30 patients (15%). Ventricular tachycardia overall occurred in 40 patients (20%). The incidence of slow VTs was low in only 12 patients (6%). No patient with slow VT suffered from syncope, palpitation, or decompensation leading to hospitalization. We did not find any reliable predictor for increased long-term risk of slow VTs. CONCLUSION Incidence of slow VTs in a typical heart failure population with primary prophylactic ICD-implantation ± resynchronization therapy is very low. Slow VTs detected in the ICD monitor zone remained clinically asymptomatic. Thus, single chamber and atriobiventricular ICDs with a VT/ventricular fibrillation zone of ≥ 187 b.p.m. and one burst before shock delivery might be sufficient and pragmatic for the vast majority of these patients.

Subcutaneous Implantable Cardioverter-Defibrillator Shocks After Left Ventricular Assist Device Implantation

A 42-year-old man experiencing nonischemic cardiomyopathy with severely reduced left ventricular function and advanced heart failure met the criteria for primary prophylactic implantation of an implantable cardioverter-defibrillator (ICD). A subcutaneous ICD (S-ICD; EMBLEM; Boston Scientific, Marlborough, MA) was implanted at a secondary center in November 2015 with the lead (3401; Boston Scientific) tunnelled in left parasternal position. Before implantation, surface ECG screening was performed following the manufacturer’s instructions. A few weeks later, the patient was transferred to Hannover Medical School because of heart failure deterioration (New York Heart Association class IV). After careful evaluation, a continuous-flow left ventricular assist device (LVAD; HeartMate 3; Thoratec, Pleasanton, CA) was implanted using conventional sternotomy.1 Approximately 1 hour after LVAD implantation, the patient received 31 S-ICD shocks. The device was immediately deactivated. Interrogation of the S-ICD revealed normal sinus rhythm during the shocks. However, R waves were diminished and superimposed by electric …