Susanne Röger

Subcutaneous implantable cardioverter-defibrillator: First single-center experience with other cardiac implantable electronic devices

BACKGROUND The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an implantable device for antiarrhythmic therapy with no intravascular leads. OBJECTIVE The purpose of this study was to describe the technical feasibility of combining the S-ICD with other cardiac implantable electronic devices (CIEDs), including pacemakers with transvenous or epicardial electrodes. We also provide the first experience of combining an S-ICD with catheter-based therapies, including cardiac contractility modulation (CCM) and vagus nerve stimulation. METHODS Between July 2011 and November 2014, 6 patients received a CCM device and S-ICD, 3 patients with a single-chamber pacemaker using either transvenous or epicardial pacing electrodes received and S-ICD, and 1 patient with an implanted S-ICD received vagus nerve stimulation. In all patients, intraoperative S-ICD testing, crosstalk tests, and postoperative ergometric testing were performed. RESULTS In all 10 patients, device implantations were successfully performed without complications. S-ICD therapy was shown to be technically feasible with concomitant CIED. Mean follow-up was nearly 17 months. S-ICD testing and crosstalk testing before and during exercise enabled device programming across a broad range of test conditions and was associated with no subsequent evidence of adverse device interaction. None of the devices required permanent inactivation or removal, and no patient received an inappropriate shock. CONCLUSION In suitable patients, combining an S-ICD with CCM or pacemaker may provide an acceptable means to reduce the number of transvascular leads. S-ICD appeared safe with CCM over an intermediate follow-up period. Additional prospective randomized controlled trials examining S-ICD in conjunction with CIEDs are warranted.

Characteristics and long-term outcome of right ventricular involvement in Takotsubo cardiomyopathy

OBJECTIVE Takotsubo cardiomyopathy, also known as stress-induced cardiomyopathy (SCM) resembles a reversible cardiomyopathy that is characterized by localized wall motion abnormalities in the absence of stenotic coronary vascular disease. Patients typically present with apical ballooning of the left ventricle (LV), however the right ventricle (RV) is also affected in up to 50.0% of patients. Long-term prognosis of classical SCM resembles that of patients after ST elevation myocardial infarction. Data on long-term prognosis of biventricular compared to classical SCM is controversial. The aim of this study was therefore to analyze patients with biventricular SCM regarding in-hospital outcome and long-term prognosis. MATERIALS AND METHODS 114 consecutive patients with SCM were retrospectively analyzed. 88 patients presented with classical SCM, 26 patients (22.8%) were diagnosed with biventricular SCM. Follow-up was conducted for a total of 4.4years. Mean age was 67.1years with 83.3% of patients being female. The primary endpoint was a composite of all-cause mortality, recurrence of SCM and re-hospitalization due to heart failure. RESULTS Although patients with biventricular SCM presented with a tendency towards an increased rate of cardiogenic shock (30.8% vs. 15.9%; p=0.09) and significantly more usage of inotropic support upon hospital admission (34.6% vs. 13.6%; p=0.01), there was no difference concerning the primary endpoint in both groups (50.0% vs. 44.3%; p=0.31). Furthermore, there was no difference in mortality both in-hospital (7.7% vs. 7.9%; p=0.66) and during long-term follow-up (27.3% vs. 23.1%; p=0.46). CONCLUSION Patients with biventricular SCM have the same in-hospital and long-term outcome compared to classical SCM.

Prevalence of cancer in Takotsubo cardiomyopathy: Short and long-term outcome

BACKGROUND Takotsubo Cardiomyopathy (TTC) is a transient disorder of ventricular wall dysfunction, mostly induced by physical or emotional stress. TTC may be associated with adverse cardiac events. The association of cancer and its clinical impact in TTC patients has not been described yet. METHODS In 114 consecutive patients presenting with TTC between January 2003 and September 2015, we studied the frequency of cancer diagnosis, and compared the clinical course and the occurrence of a clinical endpoint of cancer and non-cancer patients during a follow up of 4.2years. RESULTS Of the 114 patients, 16 (14.0%) had a malignancy already diagnosed at TTC, and further 11 patients received the diagnosis during follow up. Cancer patients had higher frequency of atrial fibrillation and lower hemoglobin levels at admission than patients without cancer. While the occurrence of in-hospital events was comparable, the diagnosis of cancer at TTC event or during follow up was predictive for a higher rate of the composite endpoint. In the Kaplan-Meier analysis, malignant diseases were strongly associated not only with overall mortality but also with worsened time of event-free survival during the long-term outcome. CONCLUSIONS Prevalence of malignant diseases is high in TTC patients, and is a risk factor for worse outcome. Screening for malignancies should be recommended in all patients presenting with TTC. Further studies are needed to define the association on molecular levels.

Simultaneous Non-Invasive Epicardial and Endocardial Mapping in Patients With Brugada Syndrome: New Insights Into Arrhythmia Mechanisms.

Background The underlying mechanisms of Brugada syndrome (BrS) are not completely understood. Recent studies provided evidence that the electrophysiological substrate, leading to electrocardiogram abnormalities and/or ventricular arrhythmias, is located in the right ventricular outflow tract (RVOT). The purpose of this study was to examine abnormalities of epicardial and endocardial local unipolar electrograms by simultaneous noninvasive mapping in patients with BrS. Methods and Results Local epicardial and endocardial unipolar electrograms were analyzed using a novel noninvasive epi‐ and endocardial electrophysiology system (NEEES) in 12 patients with BrS and 6 with right bundle branch block for comparison. Fifteen normal subjects composed the control group. Observed depolarization abnormalities included fragmented electrograms in the anatomical area of RVOT endocardially and epicardially, significantly prolonged activation time in the RVOT endocardium (65±20 vs 38±13 ms in controls; P=0.008), prolongation of the activation‐recovery interval in the RVOT epicardium (281±34 vs 247±26 ms in controls; P=0.002). Repolarization abnormalities included a larger area of ST‐segment elevation >2 mV and T‐wave inversions. Negative voltage gradient (−2.5 to −6.0 mV) between epicardium and endocardium of the RVOT was observed in 8 of 12 BrS patients, not present in patients with right bundle branch block or in controls. Conclusions Abnormalities of epicardial and endocardial electrograms associated with depolarization and repolarization properties were found using NEEES exclusively in the RVOT of BrS patients. These findings support both, depolarization and repolarization abnormalities, being operative at the same time in patients with BrS.

Cardiac contractility modulation: first experience in heart failure patients with reduced ejection fraction and permanent atrial fibrillation

AIMS Cardiac contractility modulation (CCM) is an electrical therapy for heart failure (HF) with reduced ejection fraction. Sinus rhythm is deemed necessary for effective treatment because the current CCM signal delivery algorithm requires sequential sensing of a p wave, followed by depolarizations at each ventricular lead. In case of atrial fibrillation (AF) CCM is inhibited. This study demonstrates the feasibility of CCM therapy in patients with permanent AF by circumventing the requirement for sensing of a natural p wave. METHODS AND RESULTS Five CCM patients with AF received a pacemaker or implantable cardioverter/defibrillator (ICD) upgrade to cardiac resynchronization therapy (CRT) with low atrial sensitivity, which resulted in compulsory atrial stimulation followed by biventricular pacing. The CCM system recognized the atrial stimuli as p waves, which led to CCM signal delivery. Three patients developed permanent AF after a mean follow-up of 40 months of CCM therapy. Two patients had permanent AF at the time of CCM device implantation. All pacemaker or ICD devices were successfully upgraded to CRT. Cardiac resynchronization therapy stimulation rates of ≥96% and CCM stimulation rates between 60% and 95% were achieved. Clinical condition of the patients improved (mean NYHA class -0.7, left ventricular ejection fraction +2%, Minnesota living with HF questionnaire -15.6 points). CONCLUSION CCM signal delivery is feasible in HF patients with permanent AF by sequential atrial-ventricular pacing, so that the atrial pacing spike is interpreted as a p wave by the CCM signal delivery algorithm. This experimental approach can be considered in individual cases. A new CCM algorithm, which does not require an atrial electrode, is desirable.

Long term impact of cardiac contractility modulation on QRS duration.

BACKGROUND AND PURPOSE Cardiac contractility modulation (CCM) is an implantable device treatment for heart failure with reduced ejection fraction. CCM therapy improves patient functional status but its effect on intra-ventricular conduction remains unknown. METHODS 70 patients treated with CCM between 12/2002 and 5/2013 had 12-vector-ECG recordings made at baseline and final follow-up visits. QRS complex duration was measured at each time point. RESULTS Mean follow-up was 2.8 years. Mean QRS duration was unchanged from baseline (112.0 ms) to last follow up (112.9 ms, p=n.s.). These results are strikingly different from comparative published data of several studies with heart failure patients without CCM, consistently indicating an increase in QRS duration (6.0-23.4 ms) over a similar time period. CONCLUSIONS CCM prevents chronic ventricular depolarization delay that occurs in heart failure and that is associated with poorer outcomes. This supports the safety of long-term CCM therapy and suggests a possible long-term benefit in maintaining QRS duration.

Impact and Management of Left Ventricular Function on the Prognosis of Takotsubo Syndrome

Early research has proposed that patients with Takotsubo syndrome (TTS) could have a higher mortality rate than the general population. Our study was conducted to determine the short‐ and long‐term outcome of TTS patients associated with a significantly compromised left ventricular function on hospital admission.

Long‐term results of combined cardiac contractility modulation and subcutaneous defibrillator therapy in patients with heart failure and reduced ejection fraction

Cardiac contractility modulation (CCM) is an electrical‐device therapy for patients with heart failure with reduced ejection fraction (HFrEF). Patients with left ventricular ejection fraction (LVEF) ≤35% also have indication for an implantable cardioverter‐defibrillator (ICD), and in some cases subcutaneous ICD (S‐ICD) is selected.

Low Prevalence of Inappropriate Shocks in Patients With Inherited Arrhythmia Syndromes With the Subcutaneous Implantable Defibrillator Single Center Experience and Long‐Term Follow‐Up

Background Up to 40% of patients with transvenous implantable cardioverter‐defibrillator (ICD) experience lead‐associated complications and may suffer from high complication rates when lead extraction is indicated. Subcutaneous ICD may represent a feasible alternative; however, the efficacy of the subcutaneous ICD in the detection and treatment of ventricular arrhythmias in patients with hereditary arrhythmia syndromes has not been fully evaluated. Methods and Results Patients with primary hereditary arrhythmia syndromes who fulfilled indication for defibrillator placement were eligible for enrollment. Between 2010 and 2016, 62 consecutive patients with primary hereditary arrhythmia syndromes, without indication for antibradycardia therapy, were enrolled in the study. Mean follow‐up was 31.0±14.2 months. The study cohort comprised of 24 patients with Brugada syndrome, 17 with idiopathic ventricular fibrillation, 6 with long‐QT syndrome, 1 with short‐QT syndrome, 3 with catecholaminergic polymorphic ventricular tachycardia, 8 with hypertrophic cardiomyopathy, and 3 with arrhythmogenic right ventricular cardiomyopathy. Thirty‐nine patients were implanted for secondary prevention. Twenty‐two patients had a previous transvenous ICD implanted, but required revision because of infection or lead defects. A total of 20 spontaneous ventricular tachyarrhythmias requiring shock intervention occurred in 10 patients during follow‐up. All episodes were terminated within the first ICD shock delivery with 80 J. Two patients had inappropriate therapies caused by oversensing following an uneventful implantation. No pocket‐site infections and no premature revisions have occurred during follow‐up. Conclusions Our study supports the use of the subcutaneous ICD for both secondary and primary prevention of sudden cardiac death as a reliable alternative to the conventional transvenous ICD.