Thorben König

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.

Avoiding Untimely Implantable Cardioverter/Defibrillator Implantation by Intensified Heart Failure Therapy Optimization Supported by the Wearable Cardioverter/Defibrillator-The PROLONG Study.

Background Optimal timing of implantation of an implantable cardioverter/defibrillator (ICD) after newly diagnosed heart failure is unclear given that late reverse remodelling may occur. We aimed to analyze left ventricular ejection fraction (LVEF) after diagnosis of an LVEF ≤35% during optimization of heart failure drug therapy. Methods and Results One hundred fifty‐six patients with newly diagnosed LVEF ≤35% receiving a wearable cardioverter/defibrillator (WCD) were analyzed. WCD was prescribed for 3 months until first re‐evaluation. Indications for prolongation of WCD wearing period instead of ICD implantation were: (1) LVEF at 3‐month visit 30% to 35%; (2) increase in LVEF of ≥5% compared to the last visit; and (3) nonoptimized heart failure medication. Mean LVEF was 24±7% at diagnosis and 39±11% at last follow‐up (mean, 12±10 months). Whereas 88 patients presented a primary preventive ICD indication (LVEF ≤35%) at 3‐month follow‐up, only 58 showed a persistent primary preventive ICD indication at last follow‐up. This delayed improvement in LVEF was related to nonischemic origin of cardiomyopathy, New York Heart Association functional class at baseline, heart rate, better LVEF after 3 months, and higher dosages of mineralocorticoid receptor antagonist. Twelve appropriate WCD shocks for ventricular tachycardia/ventricular fibrillation occurred in 11 patients. Two patients suffered from ventricular tachycardia/ventricular fibrillation beyond 3 months after diagnosis. Conclusions A relevant proportion of patients with newly diagnosed heart failure shows recovery of LVEF >35% beyond 3 months after initiation of heart failure therapy. To avoid untimely ICD implantation, prolongation of WCD period should be considered in these patients to prevent sudden cardiac death while allowing left ventricular reverse remodeling during intensified drug therapy.

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 …

Stable Cystatin C Serum Levels Confirm Normal Renal Function in Patients With Dronedarone-Associated Increase in Serum Creatinine

Dronedarone is a new antiarrhythmic drug for patients with nonpermanent atrial fibrillation (AF). A relatively consistent finding in all trials studying dronedarone was a moderate but significant elevation of serum creatinine. Since dronedarone competes for the same organic cation transporter in the distal renal tubule with creatinine, serum creatinine and its derived estimated glomerular filtration rate might not reflect true renal function in patients on dronedarone. We therefore investigated alternative markers for renal function in these patients. We prospectively included 20 patients with nonpermanent AF in whom dronedarone 400 mg twice daily was started. Patients had normal renal function and serum creatinine; serum cystatin C and creatinine clearance were measured before treatment and 10 and 90 days after treatment started. Mean serum creatinine level for all 20 patients at baseline (day 0) was 84.55 ± 12.14 and 87.8 ± 17.59 µmol/L on day 10. This slight increase in all patients was not significant. Patients were now divided into the predefined groups of “increased creatinine” (increase in serum creatinine level > 1 standard deviation) and “not increased creatinine.” Patients with increased creatinine levels (n = 5) showed a significant elevation of serum creatinine levels from day 0 to day 10 (82.4 ± 9.18 to 104.4 ± 12.74 µmol/L; P = .003), whereas change in serum creatinine levels in the not increased creatinine group (n = 15) was not significant. Serum cystatin C levels remained stable in both of these groups (increased creatinine group: 0.76 ± 0.08 to 0.78 ± 0.08 mg/L; P = .65; not increased creatinine group: 0.77 ± 0.108 to 0.77 ± 0.107 mg/L; P = .906). In conclusion, cystatin C represents an easily available and reliable biomarker for estimation of true renal function in patients on dronedarone treatment.

Ventricular arrhythmias in patients with newly diagnosed nonischemic cardiomyopathy: Insights from the PROLONG study: Ventricular arrhythmias in newly diagnosed non-ischemic cardiomyopathy

Patients with nonischemic cardiomyopathy (NICM) reportedly have low incidence of appropriate shocks from wearable cardioverter‐defibrillators (WCDs). A recent study questions the benefit from primary preventive implantation of implantable cardioverter‐defibrillators in NICM. We therefore analyzed a subgroup of patients with NICM from the PROLONG study.

Cardiac resynchronization therapy improves psycho-cognitive performance in patients with heart failure

BACKGROUND Reduced cognitive performance and high prevalence of depression have been reported in patients with congestive heart failure (CHF) and severe left ventricular dysfunction. However, effects of contemporary device therapy on cognitive performance and depression symptoms have not been studied thoroughly. METHODS Seventy-four consecutive CHF patients-45 receiving a biventricular defibrillator (CRT-D) and 29 receiving an implantable single or dual-chamber defibrillator (ICD) as a control group-were enrolled in this investigator-initiated, prospective, controlled, and investigator-blinded study. A set of neuropsychological tests (mini-mental state examination, DemTect, age-concentration test, and Beck depression inventory) was performed before, at 3 and at 6 months after device implantation. RESULTS DemTect-score improved significantly (F = 7.8; P = 0.007) after CRT-D-implantation compared with ICD. Age-concentration test revealed better concentration ability after CRT-D-implantation (F = 8.3; P = 0.005) compared with ICD. Under CRT-D mini-mental state examination showed a significant improvement (F = 4.2; P = 0.043). CRT with defibrillator therapy also improved depression revealed by beck depression inventory (F = 14.7; P< 0.001) compared with ICD. CONCLUSION This prospective study is the first to demonstrate psycho-cognitive improvement by resynchronization therapy in CHF patients with severe left ventricular dysfunction. In contrast to ICD therapy, the beneficial effect of CRT-D on psycho-cognitive performance might be attributed to improved cardiac function and haemodynamics.

Systematic ajmaline challenge in patients with long QT 3 syndrome caused by the most common mutation: a multicentre study.

Aims Overlap syndromes of long QT 3 syndrome (LQT3) and the Brugada syndrome (BrS) have been reported. Identification of patients with an overlapping phenotype is crucial before initiation of Class I antiarrhythmic drugs for LQT3. Aim of the present study was to elucidate the yield of ajmaline challenge in unmasking the Brugada phenotype in patients with LQT3 caused by the most common mutation, SCN5A-E1784K. Methods and results Consecutive families in tertiary referral centres diagnosed with LQT3 caused by SCN5A-E1784K were included in the study. Besides routine clinical work-up, ajmaline challenge was performed after informed consent. A total of 23 subjects (11 female, mean age 27 ± 14 years) from 4 unrelated families with a family history of sudden cardiac death and familial diagnosis of the SCN5A-E1784K mutation underwent ajmaline challenge and genetic testing. Sixteen subjects (9 female) were found to be heterozygous carriers of SCN5A-E1784K. Ajmaline challenge was positive in 12 out of the 16 (75%) mutation carriers, but negative in all non-carriers. Following ajmaline, a significant shortening of the rate-corrected JT (JTc) interval was observed in mutation carriers. The baseline JTc interval was significantly longer in mutation carriers with a positive ajmaline challenge compared with those with a negative one. Conclusion Overlap of LQT3 and BrS in patients carrying the most common mutation is high. Therefore, ajmaline challenge represents an important step to rule out potential BrS overlap in these patients before starting sodium channel blockers for the beneficial effect of QT shortening in LQT3.

Intermittent accelerated idioventricular rhythm: a novel arrhythmia in lupus erythematosus

Sir, A 32-year-old female patient was admitted to our intensive care unit (ICU) with acute pancreatitis as a manifestation of newly-diagnosed systemic lupus erythematosus (SLE). On admission, sinus rhythm was present with incomplete right bundle branch block and a heart rate (HR) of 89 bpm (Figure 1(a)). During the first night on the ICU, an intermittent ectopic ventricular rhythm with a heart rate of 83 bpm occurred (Figure 1(b) and Figure 1(c)). This rhythm had a left bundle branch block configuration without preceding P waves; however, there were P waves at the very beginning of the R wave which were not conducted via the His-Purkinje conduction system to the ventricle. As a result, there were competing atrial (sinus nodal) and ventricular rhythms at almost the same rate, representing AV dissociation and mimicking complete AV-block. This pattern was consistent with accelerated idioventricular rhythm (AIVR) originating from the right bundle branch. In our patient, conversion from AIVR to normal sinus rhythm was always characterized by a slightly increased depolarization rate of the sinus node, leading to earlier excitation of the fascicle and thereby preventing ectopy from the right bundle branch (Figure 1(d)). As such, diagnosis of AIVR is difficult, due to the very similar rates of the sinus node and the ectopic focus. In patients with SLE, new onset of conduction abnormalities such as an atrioventricular block, intraventricular disturbances and prolonged QT interval may suggest a cardiac manifestation. In this context, small vessel vasculitis and myocardial fibrosis appear to play a pivotal pathogenic role. Detection of anti-Ro/SSA antibodies in adults with SLE is associated with a prolonged QT interval, which is a risk factor for ventricular arrhythmia and sudden death in those patients. 50% of SLE patients have sinus tachycardia, which is responsive to systemic steroid treatment; however, overall life-threatening arrhythmia is rarely reported. Our patient presented with AIVR, an arrhythmia which has never been described in SLE before. The nature of this rare ventricular arrhythmia is usually benign, and anti-arrhythmic treatment or defibrillator implantation is not necessary, in most cases. Cardiac involvement by SLE can be detected by cardiac MRI, which could not be performed in our patient due to renal failure precluding the administration of MRI contrast agent; however, with continued steroids, her pancreatitis improved and AIVR did not occur anymore, suggesting both cardiac involvement and potential induction of AIVR in this case. While steroids do not have an anti-arrhythmic property per se, their administration may have ameliorated the arrhythmia by attenuating lupus-related inflammation in our case. The patient remained in sinus rhythm during the rest of her hospital stay and we recommended regular presentation to a cardiologist on an outpatient basis. The present case demonstrates the features of an intriguing arrhythmia, possibly precipitated by and first described in SLE.