Implantable loop recorder monitoring in patients with cryptogenic stroke - Detection and treatment of different clinically relevant arrhythmias.

AIMS: Implantable loop recorders (ILR) are recommended to detect atrial fibrillation (AF) in cases of cryptogenic stroke. However, real life data besides controlled trials are rare. Aim of the study was the detection of atrial fibrillation with a special focus on other arrhythmias according to criteria defined in earlier clinical trials. METHODS: We performed a retrospective analysis of 64 patients with cryptogenic stroke who underwent ILR implantation between 4/2014 and 1/2018. The primary endpoint was the detection of atrial fibrillation, significant bradycardia (<40 bpm) or tachycardia (>150 bpm). ILR interrogation was performed after implantation and 6, 12 and 24 months thereafter. RESULTS: Mean patients age was 65.4 ± 12 years, 50% were male. Mean follow-up duration was 419.2 ± 309 days. One death occurred during follow-up. 23 patients (35.9%) experienced a symptomatic clinical neurological or cardiac event during follow-up. Overall rate of detected arrhythmias was 35% (23/64). The most frequent arrhythmia was atrial fibrillation which was observed in 16 patients (25%). 6 of 16 patients presenting with atrial fibrillation had no clinical symptoms. Bradycardias requiring subsequent pacemaker implantations were detected in 9.4%. A ventricular tachycardia was observed in one patient (1.6%). CONCLUSION: In this group of patients with cryptogenic stroke the rate of arrhythmic events was high. Besides a high rate of atrial fibrillation (25%), an unexpectedly high rate of bradyarrhythmias (9.4%) occurred in our patient collective. Since many of those episodes were clinically asymptomatic, the ILR helps to detect and treat those clinically silent arrhythmias.

Age-dependent clinical and echocardiographic manifestations of aortic stenosis in an unselected, non-biased cohort.

BACKGROUND: Age, clinical presentation and echocardiographic parameters are important factors in the decision on an individualized therapeutic strategy for patients with aortic stenosis (AS). Less is known about this information in a non-selected non-biased cohort. METHODS: We performed a retrospective, systematic analysis of patients admitted to our hospital from 1/1/2014 to 1/6/2018 with the diagnosis of AS. We collected demographic, clinical and echocardiographic parameters. All patients were evaluated and treated in one single institution by experienced cardiologists. We classified patients into 4 age groups to compare the above-mentioned variables. Category A: patients younger than 65 years, category B age between 65-74, category C age between 75-84, and category D patients older 85. RESULTS: We included 321 adults with AS in our study. There was a significant correlation between the aortic valve area, aortic velocity (Vmax), aortic pressure gradients (PMax) and age. The AVA decreased, Vmax and PMax increased with age (P=0.001, P=0.042 and P=0.017, respectively). 74.1% of all patients were symptomatic, but there were no differences between the age categories (P=0.406). The incidence of cardiovascular comorbidities was high throughout all age categories. Forty-four point five percent of all patients had a coronary artery disease, but there were no differences between the age categories (P=0.221). Echocardiographic aspect of AS was similar in all age groups except the right ventricular pressure (RVP): RVP was significantly higher in patients younger than 65 years. CONCLUSIONS: Based on our results, we conclude that age is a weak parameter for making decisions about the optimal AS therapy. AVAs in AS decreases moderately with age. Age does not impact any clinical or echocardiographic parameters. Cardiovascular diseases and symptomatic AS are found in all age categories.

Bleeding risk of submuscular ICD implantation with continued oral anticoagulation versus heparin bridging therapy.

Recent studies have shown that subcutaneous or subfascial pacemaker- and ICD implantation with continued oral anticoagulation therapy is associated with lower risk for bleeding complications, when compared to heparin bridging strategies. However, ICD generators are often implanted submuscularly. We therefore compared the bleeding risk with continued phenprocoumon therapy vs. heparin bridging in patients receiving submuscular ICD implantation. Between 01/2013 and 12/2013, 104 patients with need for oral anticoagulation received submuscular ICD or CRT-D implantation in our institution. 46 patients were implanted under continued phenprocoumon therapy while 58 patients received heparin bridging for implantation procedure. All ICD generators were placed submuscularly. The primary outcome of the study was clinically significant bleeding or device pocket hematoma with need for surgical revision. Mean patients age was 63.7 years, 72.1% were male. In patients with heparin bridging therapy, preoperative INR prior to ICD implantation was 1.2 ± 0.31 while in the group of patients on continued phenprocoumon therapy, mean pre-OP INR was 2.4 ± 0.47. In heparin bridging group, 8 (13.8%) patients experienced a clinically relevant pocket hematoma, while only 1 (2.2%) patient on continued phenprocoumon therapy needed surgical revision for pocket hematoma (P = 0.04). No further bleeding complications or clinically relevant pericardial effusion was observed in any of the groups and no perioperative thromboembolic event occurred. Submuscular ICD implantation under continued phenprocoumon therapy was safe and feasible. Compared to patients with heparin bridging therapy, those with continued phenprocoumon therapy had a lower incidence of clinically relevant bleeding complications.

High Incidence of De Novo and Subclinical Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy and Cardiac Rhythm Management Device.

INTRODUCTION: Atrial fibrillation (AF) is an important prognostic parameter in patients with hypertrophic cardiomyopathy (HCM). Though cardiac rhythm management (CRM) devices (e.g., ICD, pacemaker or implantable loop recorder) can detect subclinical AF, data describing the incidence of AF are rare. We therefore investigated the incidence and clinical impact of de novo and subclinical AF detected by CRM devices in patients with HCM. METHODS AND RESULTS: In our retrospective single-center study, we included patients with HCM and need for CRM devices. The primary endpoint of the study was the incidence of clinical and subclinical de novo AF. During follow-up, patients were screened for adverse events like stroke, ventricular arrhythmia, heart failure, or death. From 192 HCM patients, 44 patients received a CRM device (38 ICDs, 5 pacemakers, 1 implantable loop recorder). In 14 of these patients (32%), AF had been documented before device implantation. Thirty (68%) patients were free from AF at the time of implantation. During a median follow-up of 595 days (interquartile range, 367-890 days), de novo AF was recorded in 16 of these 30 patients (53%). Fourteen (88%) of the 16 patients with de novo AF were free from any clinical symptoms, so these patients were classified to have subclinical AF. In logistic regression analysis, age was the only significant predictor for an increased risk of AF. CONCLUSION: AF is common in patients with HCM who need a CRM device. More than 50% of these patients develop de novo AF that was predominantly subclinical in our cohort.

Pulse wave analysis of the aortic pressure waveform in patients with vasovagal syncope.

Vascular reflex mechanisms contribute to vasovagal syncope. However, the alterations in central haemodynamics in patients with vasovagal syncope are unknown. 30 consecutive patients (36.5 ± 15 years, 14 females) with recurrent vasovagal syncope (VVS) and a positive tilt table test were compared to 39 age- and sex-matched controls (36.9 ± 16 years, 15 females) with a negative tilt table result and no history of syncope. Central aortic pressure parameters including augmentation index and central pulse pressure as markers of aortic stiffness were generated non-invasively by applanation tonometry of the radial artery and use of a validated mathematical transfer function. No difference in aortic augmentation index was observed between groups. (VVS 9 ± 2.6 vs. Control 11 ± 2.4, p = 0.8). However, in patients with vasovagal syncope the aortic pressure waveform significantly differed from healthy controls. A prolonged time to the peak of aortic pressure wave (aortic T2) was observed in patients with vasovagal syncope (226 ± 24 vs. 208 ± 21 ms, p = 0.001). Furthermore time to the first shoulder of the aortic pressure wave (aortic T1) was slightly shorter compared to healthy controls, but did not reach statistical significance (106 ± 22 vs. 110 ± 12 ms, p = 0.33). Patients with vasovagal syncope have an altered aortic pressure waveform at rest, but no signs of elevated aortic stiffness. The underlying mechanisms for these findings may potentially result from a complex imbalance of the autonomic nervous system with a continuous deregulation of the sympathetic and parasympathetic reflex arcs.

Clinical experience of combined HeartWare ventricular assist device and implantable cardioverter defibrillator therapy.

INTRODUCTION: The HeartWare continuous flow ventricular assist device (HVAD) is used in an increasing number of heart failure patients. In those patients, ventricular arrhythmias (VAs) are common and, consequently, many patients already have an implanted implantable cardioverter defibrillator (ICD) in place or receive ICD implantation after left ventricular assist device implantation. However, limited data on feasibility and necessity of combined ICD and HVAD therapy are available. In this study we present our technical and clinical experience. METHODS AND RESULTS: Between 01/2010 and 06/2013, 41 patients received HVAD implantation. Twenty-six HVAD patients who already had an ICD device placed prior to HVAD implantation or received ICD implantation afterwards were enrolled in this study. Peri- and postoperative complications as well as ICD interrogations were documented and analyzed retrospectively. Mean patients age was 58.4 ± 12.6 years; 88.5% of patients were male. During mean follow-up of 12.2 ± 8.9 months, appropriate ICD interventions occurred in 9 patients (34.6%) due to ventricular tachyarrhythmia (n = 7) or ventricular fibrillation (n = 2). An inappropriate ICD intervention was seen in 1 patient (3.9%) due to tachycardic atrial fibrillation. Patients on HVAD with a history of VAs (n = 13) had a significantly higher incidence of ICD interventions compared to patients with primary prophylactic indication for ICD (n = 13; 53.8% vs. 7.7%; P = 0.015). No disturbance of ICD function was seen after HVAD implantation. CONCLUSION: Combined ICD and HVAD therapy was safe and feasible, without electromagnetic interference between ICD and ventricular assist device. The incidence of ICD interventions was high in patients with a history of VAs, but low in patients with ICD implantation for primary prevention.

Transcutaneous lead implantation connected to an externalized pacemaker in patients with implantable cardiac defibrillator/pacemaker infection and pacemaker dependency.

AIMS: Systemic cardiac implantable electronic device (CIED) infection is a serious complication, especially in patients with pacemaker (PM) dependency. In those patients after infectious device removal temporary pacing is necessary, to obtain adequate haemodynamics. In this study, a new therapy option with temporary pacing by ipsilateral implantation of a new active-fixation right ventricular (RV)-lead was evaluated. METHODS AND RESULTS: Between September 2009 and November 2011, infectious lead removal was performed in 17 patients with systemic CIED infection. Temporary pacing was achieved by simultaneous implantation of a new active-fixation RV-lead, which then was connected extracorporally to the old CIED device. Antibiotic therapy was initiated. When laboratory infection parameters were in normal range and blood culture samples showed negative results, new CIED was implanted on contralateral side and temporary RV-lead was removed. Mean patients' age was 71.3 ± 9.1 years. Mean C-reactive protein values were 79.3 mg/dL, and mean leucocytes counts were 12.6 × 10(3). After lead extraction, temporary pacing was necessary in all patients due to severe bradycardia. Mean duration of temporary pacing was 12.7 (6-24) days. No major procedure-related peri- or post-operative adverse events occurred. Mean time of hospitalization was 20.8 (10-48) days. Mean follow-up time was 21.1 months (12-36), showing survival rate of 100% and freedom from reinfection in all patients. CONCLUSION: Ipsilateral implantation of a temporary active-fixation RV-lead connected to an externalized PM and pursued antibiotic therapy seems to be a good option for patients with CIED infection and PM dependency, showing no temporary pacing-related complications and no reinfection after mean follow-up time of 21.1 months.

Shock efficacy of subcutaneous implantable cardioverter-defibrillator for prevention of sudden cardiac death: initial multicenter experience.

BACKGROUND: Recently, subcutaneous implantable cardioverter-defibrillator (S-ICD) has become available. The aim of our study was to assess the efficacy of S-ICD in a clinical setting. METHODS AND RESULTS: Between June 2010 and July 2011, 40 consecutive patients (42 ± 15 years; body mass index, 27 ± 6 kg/m(2); left ventricular ejection fraction, 47 ± 15%; 28 men) received an S-ICD for primary (n=17) or secondary prevention (n=23 [58%]) at 3 institutions in Germany. Intraoperative defibrillation efficacy testing failed in 1 patient with severely reduced left ventricular ejection fraction; testing was effective in all other patients. All episodes stored in the S-ICD were analyzed for appropriate and inappropriate detection, as well as effective shock delivery to convert ventricular tachyarrhythmia into sinus rhythm. During a median follow-up of 229 (interquartile range, 116-305) days, 4 patients experienced 21 episodes, with correct detection of ventricular tachyarrhythmia and subsequent shock therapy. A total of 28 shocks were delivered in these 4 patients. Mixed logistic regression modeling revealed a shock efficacy of 96.4% (95% CI, 12.8%-100%). The efficacy of first shocks, however, was only 57.9% (95% CI, 35.6%-77.4%). Four episodes were incorrectly classified as ventricular tachyarrhythmia, which led to inappropriate shock delivery in 2 patients. CONCLUSIONS: Ineffective shock delivery may occur in patients with S-ICD, even after successful intraoperative testing. Multicenter trials are required with close monitoring of safety and efficacy end points to identify patients who may be at risk for shock failure.

A standardized education protocol significantly reduces traumatic injuries and syncope recurrence: an observational study in 316 patients with vasovagal syncope.

AIMS: The aim of this study was to assess the role of a non-pharmacological approach on the frequency of traumatic injuries and syncope recurrence in patients with vasovagal syncope and normal hearts. We report the experience in our syncope centre with a standardized education and teaching protocol for patients with vasovagal syncope. The treatment of vasovagal syncope is often complex and discouraging. Besides medical options, behaviour modification is a main component of therapy but has no statistical evidence to support its use. METHODS AND RESULTS: Between January 1999 and September 2006, we prospectively enrolled all patients with vasovagal syncope. The patients were counselled about the benign nature of their disease. Specific recommendations were made according to a standardized education protocol established at our syncope centre. A pre-/post-study was conducted to investigate the effectiveness of our approach on syncope recurrence and frequency of injury as the study endpoints. Complete follow-up data were available from 85% of the study population (316 of 371) after a mean time of 710 ± 286 days (mean age 50 years; standard deviation ± 18 years, 160 female). Eighty-seven patients (27.5%) had a syncope recurrence with 22 suffering an injury during syncope. During the follow-up period, the syncope burden per month was significantly reduced from 0.35 ± 0.03 at initial presentation to 0.08 ± 0.02 (P< 0.001). The frequency of traumatic syncope was significantly lower at the time of recurrence compared with the initial presentation (25 vs. 42%; McNemar's test P= 0.02). CONCLUSION: A standardized education protocol significantly reduces traumatic injuries and syncope recurrence in patients with vasovagal syncope.

Management and therapy of vasovagal syncope: A review.

Vasovagal syncope is a common cause of recurrent syncope. Clinically, these episodes may present as an isolated event with an identifiable trigger, or manifest as a cluster of recurrent episodes warranting intensive evaluation. The mechanism of vasovagal syncope is incompletely understood. Diagnostic tools such as implantable loop recorders may facilitate the identification of patients with arrhythmia mimicking benign vasovagal syncope. This review focuses on the management of vasovagal syncope and discusses the non-pharmacological and pharmacological treatment options, especially the use of midodrine and selective serotonin reuptake inhibitors. The role of cardiac pacing may be meaningful for a subgroup of patients who manifest severe bradycardia or asystole but this still remains controversial.

Effects of aging on reflex autonomic nervous response induced by orthostatic maneuvers.

BACKGROUND: Baroreflex sensitivity (BRS), exercise pressor reflex (EPR), and aging influence the autonomic nervous response associated with orthostatic maneuvers. Standing significantly increases heart rate (HR), with an initial increase (1.deltaHR) due to EPR and a secondary, more gradual increase (2.deltaHR) due to BRS. HR then decreases (3.deltaHR), which is also attributable to BRS. Thus far, however, few data are available regarding the interdependence of these variables. METHODS AND RESULTS: Ninety-five healthy volunteers (mean age 37 +/- 11 years, range 10-70 years; 50 women) underwent continuous noninvasive measurements of beat-to-beat blood pressure, HR, and spontaneous BRS in the supine (10 minutes) and upright (10 minutes) positions. After tilt, 1.deltaHR, 2.deltaHR, and 3.deltaHR were calculated from the HR recording. From the 1(st) to the 6(th) decade BRS, 2.deltaHR and 3.deltaHR decreased with normal aging ([BRS 11.88 +/- 7.97 ms/mmHg to 1.81 ms/mmHg, P = 0.006], 2.deltaHR [16.75 +/- 3.40 beats to 5.33 +/- 2.52 beats, P = 0.002], 3.deltaHR [52.25 +/- 5.91 beats to 11.33 +/- 4.04 beats, P < 0.001]). However, no such association was noted between 1.deltaHR and age (21.25 +/- 9.35 beats to 12.00 +/- 7.21 beats, ns). BRS while standing was correlated with 1.deltaHR (r = 0.432, P < 0.001). CONCLUSIONS: EPR, in contrast to BRS, was not significantly influenced by normal aging. Furthermore, not only was BRS influenced by EPR, as is generally acknowledged, but EPR and BRS were interrelated. These observations offer new insights into the complex interactions of orthostasis-induced physiological autonomic reflexes associated with normal aging.

Modulation of cardiac autonomic nervous activity early after cardioversion of atrial fibrillation by biphasic waveform.

BACKGROUND: Imbalance of cardiac autonomic nervous modulation might prominently contribute to early relapses of atrial fibrillation (AF) after cardioversion (CV). The biphasic (Bi) waveform is more effective than the monophasic (Mo) waveform in CV of AF. Whether these waveforms have different effects on autonomic modulation early after CV is unknown. METHODS: We investigated 171 consecutive patients after successful electrical CV (mean age 65.4 years, 82% male, 80% structural heart disease). Bi waveform was used in 89, Mo waveform in 82. Heart rate variability (HRV) was analyzed from 24-hour Holter recordings, started directly after CV. RESULTS: Mean delivered total energy was significantly lower in the Bi group (Bi 223 +/- 163 W, Mo 355 +/- 211 W, P < 0.001). Mean RR interval decreased within 5 hours after CV and increased again within the remaining hours, without significant differences between Bi and Mo groups. Time courses of time domain parameters of HRV revealed Bi profiles with the lowest levels 6 hours after CV in both groups. However, the hourly values of HRV were significantly higher in the Bi subgroup. CONCLUSION: Our study indicates that waveform and total delivered energy significantly influence autonomic modulation of the sinus node in the early phase after CV of AF. In contrast to Bi CV, Mo CV is characterized by a significant decrease of cardiac vagal modulation, which may have an arrhythmic effect by increasing the degree of early electrical stunning after CV of AF.

Inadequate ICD discharges due to diaphragmatic electromyopotential oversensing as the first sign of right ventricular lead perforation.

Right ventricular lead perforation, when acute, is a rare but potentially life-threatening complication of implantable cardioverter defibrillator (ICD) therapy. We report about a patient with early lead perforation presenting with repetitive ICD discharges due to oversensing of diaphragmatic electromyopotentials and describe the management of this complication.

Ventricular fibrillation induced by stretch pulse: implications for sudden death due to commotio cordis.

INTRODUCTION: Nonpenetrating chest wall impact (commotio cordis) may lead to sudden cardiac death due to the acute initiation of ventricular fibrillation (VF). VF may result from sudden stretch during a vulnerable window, which is determined by repolarization inhomogeneity. METHODS: We examined action potential morphologies and VF inducibility in response to sudden myocardial stretch in the left ventricle (LV). In six Langendorff perfused rabbit hearts, the LV was instrumented with a fluid-filled balloon. Increasing volume and pressure pulses were applied at different times of the cardiac cycle. Monophasic action potentials (MAPs) were recorded simultaneously from five LV epicardial sites. Inter-site dispersion of repolarization was calculated in the time and voltage domains. RESULTS: Sudden balloon inflation induced VF when pressure pulses of 208-289 mmHg were applied within a window of 35-88 msec after MAP upstroke, a period of intrinsic increase in repolarization dispersion. During the pressure pulse, MAPs revealed an additional increase in repolarization dispersion (time domain) by 9 +/- 6 msec (P < 0.01). The maximal difference in repolarization levels (voltage domain) between sites increased from 19 +/- 3% to 26 +/- 3% (P < 0.05). Earliest stretch-induced activation was observed near a site with early repolarization, while sites with late repolarization showed delayed activation. CONCLUSIONS: Sudden myocardial stretch can elicit VF when it occurs during a vulnerable window that is based on repolarization inhomogeneity. Stretch pulses applied during this vulnerable window can lead to nonuniform activation. Repolarization dispersion might play a crucial role in the occurrence of fatal tachyarrhythmias during commotio cordis.