Remote detection of incessant slow VT with an ICD capable of home monitoring.

In this case report, we present a 57-year-old patient who suffered from incessant slow ventricular tachycardia because of a change in therapy 2 weeks after the implantation of an implantable cardioverter defibrillator (ICD) with Home Monitoring (HM). HM is a fully automatic and wireless system capable of transmitting device data including episode counters. The patient had mild symptoms with only short episodes of dizziness and would not have contacted the primary care centre. Due to HM, the arrhythmia was detected before the next routine follow-up, and the patient was seen the next day. HM made it possible to adjust the dosage of the newly established beta-blocker treatment in an outpatient setting and avoid hospitalization. HM yields the potential for remote detection of arrhythmias in ICD recipients, allowing alterations in device programming or medication.

Discordant regulation of CRP and NT-proBNP plasma levels after electrical cardioversion of persistent atrial fibrillation.

BACKGROUND: B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been suggested to be prognostically relevant markers in patients with cardiovascular disease. Additionally, BNP and CRP plasma levels seem to be independently elevated in patients with atrial fibrillation (AF). However, there are only sparse data about the significance and temporal course of these plasma markers after restoration of sinus rhythm (SR). METHODS: We performed a prospective study in consecutive patients with symptomatic atrial fibrillation. NT-proBNP and CRP plasma levels were measured before and one month after electrical cardioversion (CV). Patients with infections, an acute coronary syndrome, or surgery 4 weeks prior to CV, were excluded. RESULT: Twenty-five patients (men 84%, age 66 +/- 8 years, duration of AF 90 +/- 75 days, left ventricular ejection fraction 0.57 +/- 0.11) were analyzed. At follow-up (33 +/- 6 days after CV) 14 patients (56%) were in SR and 11 patients (44%) in AF. In patients with SR there was a significant reduction of NT-proBNP levels (baseline 1647 +/- 1272 pg/mL, follow-up 772 +/- 866 pg/mL, P < 0.05), even in a subgroup of patients (n = 10) with normal left ventricular ejection fraction (1262 +/- 538 vs 413 +/- 344 pg/mL, P < 0.001). CRP levels in patients with SR were similar at baseline and at follow-up (3.5 +/- 3.6 vs 3.2 +/- 2.5 mg/L, P = 0.8). CONCLUSION: We conclude that even in patients with normal left ventricular ejection fraction restoration of sinus rhythm leads to a significant reduction of NT-proBNP plasma levels. In contrast, CRP plasma levels seem not to be influenced during the first 4 weeks after electrical cardioversion.

Outpatient electrical cardioversion of atrial fibrillation: efficacy, safety and patients' quality of life.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia. To lower costs and to reduce hospitalization electrical cardioversion (CV) is frequently performed in an outpatient setting although data on safety and patient-acceptance are sparse. Aims of this study were to fill this gap by evaluating efficacy, complication rate, quality of life after CV and patient-acceptance of outpatient CV. METHODS: One-hundred and eleven consecutive patients with persistent AF were included. Patients were under continuous monitoring throughout the procedure and 3 h after. CV was done in deep sedation using rising energies (200->360 J). Quality of life (QoL), late adverse events and patient-acceptance were assessed 4 weeks after CV. RESULTS: AF could be terminated with a mean of 1.4 shocks in all patients. Acute adverse events could be observed in 3.6%. Late adverse events were noted in 8.2%. Seventy-four percent of the patients felt "good" or "very good" the day of CV. Eighty-nine percent of the patients would undergo a CV again and in case of a further CV 69% of the patients would prefer an outpatient setting. Patients with a lower QoL-classification had longer duration of atrial fibrillation (median 1 vs. 3 months, p<0.05). No other clinical predictor for adverse events or a low QoL-classification could be identified. CONCLUSION: Electrical CV of persistent AF in an outpatient setting is feasible, safe and has a high patient-acceptance.

Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation.

BACKGROUND: In biphasic external cardioversion (CV) of atrial fibrillation (AF), the influence of different electrode positions on efficacy and incidence of early recurrent atrial fibrillation is not known. This study compared anteroposterior (AP) vs anterolateral (AL) electrode positioning. METHODS: Consecutive patients referred for CV of persistent AF were randomized either to an AP or an AL electrode position. Biphasic external CV was performed with standardized electrode positions and rising energy delivery. RESULTS: Both groups (N = 123, mean age 66 years, 71% male, 83% with structural cardiovascular disease or hypertension) did not differ concerning age, sex, body mass index, chronic antiarrhythmic therapy, duration of AF, left ventricular ejection fraction, and left atrial diameter. Cumulative success rates were comparable (AP 94.9% vs AL 95.2%, P = ns). First-shock efficacy did not differ (AP 78.3% vs AL 74.6%, P = ns). Early recurrent atrial fibrillation (AF relapse < 1 minute after successful CV) occurred in 8.1% (AP 11.6% vs AL 4.8%, P = ns). Mean number of shocks was 1.3 per patient with the AP configuration and 1.4 per patient with the AL configuration (P = ns). Mean cumulative energy delivery was also comparable (AP 171 WS vs AL 198 WS, P = ns). CONCLUSIONS: Both electrode positions are similar in biphasic external CV of AF with regard to acute success and early recurrent atrial fibrillation. Also, the number of shocks needed and energy delivery are comparable with both electrode configurations.

Impact of biphasic electrical cardioversion of atrial fibrillation on early recurrent atrial fibrillation and shock efficacy.

INTRODUCTION: Early recurrent atrial fibrillation (ERAF) after external cardioversion of atrial fibrillation (AF) occurs in 12% to 26% of patients. Whether biphasic cardioversion has an impact on the incidence of ERAF after cardioversion of AF is unclear. METHODS AND RESULTS: Consecutive patients (n = 216, mean age 66 years, 71% male, 88% with structural cardiovascular disease or hypertension) underwent cardioversion with a biphasic (Bi) or monophasic (Mo) shock waveform in randomized fashion. Energies used were 120-150-200-200 Ws (Bi) or 200-300-360-360 Ws (Mo). The two study groups (Bi vs Mo) did not differ with regard to age, sex, body mass index, underlying cardiovascular disease, left atrial diameter, left ventricular ejection fraction, duration of AF fibrillation, and antiarrhythmic drug therapy. Mean delivered energy was significantly lower in the Bi group (Bi: 186 +/- 143 Ws vs Mo: 324 +/- 227 Ws; P < 0.001). Overall incidence of ERAF (AF relapse within 1 minute after successful cardioversion) was 8.9% and showed no difference between the two groups (Bi: 8.1% vs Mo: 9.7%, P = NS). Cardioversion was successful in 95.4% of patients. The success rate was comparable in both groups (Bi: 94.3% vs Mo 96.8%; P = NS). First shock efficacy did not differ between Bi and Mo (76.4% vs 67.7%; P = NS). Mean number of shocks were 1.4 shocks per patient in both groups. CONCLUSION: Biphasic cardioversion allows comparable success rates with significantly lower energies. However, the incidence of ERAF is not influenced by biphasic cardioversion. With the energies used, biphasic and monophasic shock waveforms are comparable with regard to first shock and cumulative shock efficacy.

Clinical value of routine predischarge testing after ICD-implantation.

AIMS: After implantation of a cardioverter/defibrillator (ICD) predischarge testing is often performed to ensure appropriate therapy function. Nevertheless there is no proven evidence for the necessity of this examination. In this retrospective single-centre analysis we investigated the clinical value of routine predischarge testing. METHODS AND RESULTS: Predischarge testing was performed in 161 patients 6+/-2 days after primary implantation of an ICD. There were no complications related to ICD-testing. In 17 of 161 patients (11%) there was at least one pathological finding. In 4 of 17 patients we observed a defibrillation energy requirement (DER) with a safety margin of less than 10J. In two of these patients an early lead repositioning was undertaken and in two patients reversal of the shock polarity was used to achieve an adequate DER. In 13 of 17 patients we detected a distinct deviation of pacing thresholds or R-wave sensing amplitudes. In two of these patients an early electrode repositioning was performed because of lead displacement. In the remaining 11 patients we found an adequate DER at first, whereas in two patients a further lead repositioning was still necessary during follow-up. In 144 of 161 patients (89%) predischarge testing was without pathological findings. None of these patients needed revision of the ICD-lead during a mean follow-up of 24+/-13 months. CONCLUSIONS: Abnormal measurements during predischarge testing are not rare findings in ICD-recipients. Noninvasive methods cannot rule out inadequate defibrillation function. A normal predischarge test seems to be a reliable predictor for a stable electrode function during the first years of follow-up.

Incidence and management of early recurrent atrial fibrillation (ERAF) after transthoracic electrical cardioversion.

AIMS: The purpose was to determine the incidence of early recurrent atrial fibrillation (ERAF) after transthoracic cardioversion (CV) of persistent atrial fibrillation (AF) and to evaluate the efficacy of a predefined strategy for its management. METHODS AND RESULTS: Consecutive patients (n=135) underwent elective CV of AF. CV was performed according to a predefined step-up protocol with rising energy delivery (200 J to 360 J). ERAF was defined as a relapse of AF within 1 min after at least two sinus beats. For proper identification of success of CV, additional endocardial recordings were obtained by an electrode catheter positioned in the high right atrium. In case of ERAF, further CVs were attempted, first with higher energy delivery only, second after intravenous flecainide. If transthoracic CV was ineffective, an internal CV was scheduled. All patients could be converted into sinus rhythm. Sixteen patients (12%) had ERAF. ERAF could be suppressed by further shock delivery in 31% of them. In the remaining 69%, a combination of i.v. flecainide and repeated CV was effective in controlling ERAF. Clinical and echocardiographic parameters were comparable in patients with or without ERAF. CONCLUSION: (1) In the patient population studied, transthoracic CV of AF was technically highly efficacious, so that an internal CV was not necessary in any of the cases. (2) Clinical success of transthoracic cardioversion was limited by ERAF in 12% of the patients. (3) Using the described protocol, ERAF could be suppressed in all patients.

Defibrillation efficacy and pain perception of two biphasic waveforms for internal cardioversion of atrial fibrillation.

UNLABELLED: Efficacy and Pain Perception of Two Biphasic Waveforms. INTRODUCTION: We evaluated the influence of the peak voltage of waveforms used for internal cardioversion of atrial fibrillation on defibrillation efficacy and pain perception. A low peak voltage biphasic waveform generated by a 500-microF capacitor with 40% tilt was compared to a standard biphasic waveform generated by a 60-microF capacitor with 80% tilt. METHODS AND RESULTS: In 19 patients with paroxysmal atrial fibrillation (79% male, age 55 +/- 11 years, 21% with heart disease), the atrial defibrillation threshold (ADFT) was determined during deep sedation with midazolam for both waveforms in a randomized fashion using a step-up protocol. Internal cardioversion with a single lead (shock vector: coronary sinus to right atrium) was successful in 18 (95%) of 19 patients. ADFT energy and peak voltage were significantly lower for the low-voltage waveform (2.1 +/- 2.4 J vs 3.5 +/- 3.9 J, P < 0.01; 100 +/- 53 V vs 290 +/- 149 V, P < 0.01). Sedation then was reversed with flumazenil after ADFT testing. Two shocks at the ADFT (or a 3-J shock if ADFT >3 J) were administered to the patient using each waveform in random order. Pain perception was assessed using both a visual scale and a numerical score. ADFTs were above the pain threshold in 17 (94%) of 18 patients, even though the ADFT with the 500-microF waveform was <100 V in 63% of the patients. Pain perception was comparable for both waveforms (numerical score: 6.5 +/- 2.4 vs 6.3 +/- 2.6; visual scale: 5.4 +/- 2.6 vs 5.2 +/- 3.1; P = NS, 500-microF vs 60-microF). The second shock was perceived as more painful in 88% of the patients, independent of the waveform used. CONCLUSION: Despite a 66% lower peak voltage and a 40% lower energy, the 40% tilt, 500-microF capacitor biphasic waveform did not change the pain perceived by the patient during delivery of internal cardioversion shocks. Pain perception for internal cardioversion probably is not influenced by peak voltage alone and increases with the number of applied shocks.

Focal parvovirus B19 myocarditis in a patient with Brugada syndrome.

The Brugada syndrome is characterized by a distinct ECG pattern consisting of ST segment elevation in the right precordial leads and right bundle branch block, a propensity for life-threatening arrhythmias, and an apparently structurally normal heart. The authors describe the case of a patient with an aborted sudden cardiac death and the typical ECG signs of Brugada syndrome. Nevertheless, magnetic resonance imaging displayed signal enhancement in the left ventricular myocardium. Additionally, histologic examination, in-situ hybridization, and PCR revealed evidence of a locally restricted inflammation due to parvovirus B19. Brugada syndrome is regarded as a primary electrical disease due to dysfunction of distinctive ion channels, but focal myocarditis may serve as a trigger for ventricular arrhythmias in this patient. Further morphologic studies will be helpful to establish the possible role of structural changes in the pathophysiology of this syndrome.