Shunsuke Uetake

Recovery of atrioventricular block following steroid therapy in patients with cardiac sarcoidosis

BACKGROUND Atrioventricular (AV) block is one of the main clinical manifestations in patients with cardiac sarcoidosis (CS). Although steroid therapy is considered to be effective for AV block, the efficacy has not been demonstrated in detail. METHODS AND RESULTS Fifteen CS patients presenting with advanced or complete AV block were retrospectively investigated. All patients were treated with 30mg/day of prednisone after device implantation, which was tapered to a maintenance dosage of 5-10mg/day. During a mean follow-up of 7.1 years, AV block resolved to normal conduction or first-degree AV block in 7 patients (recovery group). The improvement was driven within the first week of steroid therapy in 4 patients, while 3 patients showed late recovery of AV conduction. The remaining 8 patients were classified as the non-recovery group. The recovery group showed a higher left ventricular ejection fraction (69.4±8.9% versus 44.1±19.3%, p=0.029) and higher prevalence of advanced AV block (87.5% versus 28.6%, p=0.040) compared with those of the non-recovery group. In patients with the recovery group, there was no late recurrence of AV block during the follow-up period. CONCLUSIONS Early initiation of steroid therapy may be effective for AV block, and steroid therapy before device implantation is a possible therapeutic strategy for some selected patients.

Urgent catheter ablation for sustained ventricular tachyarrhythmias in patients with acute heart failure decompensation

AIMS Ventricular tachycardia (VT) and ventricular fibrillation (VF) are not uncommon in patients hospitalized with acute heart failure (AHF). We sought to evaluate the efficacy of urgent radiofrequency catheter ablation (RFCA) for recurrent VT/VF during AHF decompensations. METHODS AND RESULTS The present study retrospectively analysed the data of 15 consecutive patients (69 ± 9 years, ischaemic heart disease in 10), who underwent urgent RFCA for frequent drug-refractory VT/VF episodes during an AHF decompensation with pulmonary congestion. The target arrhythmias were clinically documented monomorphic VTs in 10 patients, frequent premature ventricular contractions (PVCs) triggering VF in 4, and both in 1. The mean left ventricular ejection fraction was 26 ± 8%. The maximum number of arrhythmia episodes over 24 h was 9.1 ± 11.7. All RFCA sessions were completed without any major complications except for a temporary deterioration of pulmonary congestion in three patients (20%). Elimination and non-inducibility of the target arrhythmias were achieved in 13 patients (87%). Successful ablation site electrograms showed Purkinje potentials for all 5 PVCs triggering VF and 4 of 14 clinically documented monomorphic VTs (29%). Five patients (33%) underwent second sessions 10 ± 4 days after the first session for acute recurrences. Sustained VT/VF was completely suppressed during admission in 12 patients (80%), and the AHF ameliorated in 13 patients (93%). Twelve patients (80%) were discharged alive. CONCLUSION Urgent RFCA for drug-resistant sustained ventricular tachyarrhythmias during AHF decompensations would be an appropriate therapeutic option. Purkinje fibres can be ablation targets not only in those with PVCs triggering VF, but also in those with monomorphic VT.

Three-month lower-dose flecainide after catheter ablation of atrial fibrillation

AIMS Atrial tachyarrhythmias (AT) commonly recur within the first 3 months after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF), and the influence of antiarrhythmic drugs (AADs) on the recurrences has not been fully elucidated. We sought to evaluate the efficacy of a 3-month lower-dose flecainide regime on early and late recurrences of ATs. METHODS AND RESULTS We randomly assigned 126 patients, who underwent RFCA for AF, to the flecainide group (150 or 100 mg/day according to their body weight) or to the control group receiving no AADs. The primary endpoint was any AT lasting for ≥30 s during the first 3 months and the secondary endpoint was a composite of ATs lasting for ≥24 h or requiring cardioversion or hospitalization during the same period. All AADs were stopped after the first 3 months and the late arrhythmia recurrences were also evaluated. The primary endpoint rates were 37 and 41% in the flecainide (143 ± 19 mg/day) and control groups, respectively (log-rank P = 0.76), and those of the secondary endpoint were 10 and 14%, respectively (log-rank P = 0.45). The estimated rates of maintaining sinus rhythm at 12 months after the first 3 months were 78 and 72%, in the flecainide and control groups, respectively (log-rank P = 0.68), and the rates were 51 and 90% in those with and without the primary endpoint, respectively (log-rank P < 0.001). CONCLUSION The 3-month lower-dose flecainide therapy after AF ablation did not reduce the early and late arrhythmia recurrences. The clinically significant ATs were also not prevented.

Clinical and Electrocardiographic Characteristics of Electrical Storms Due to Monomorphic Ventricular Tachycardia Refractory to Intravenous Amiodarone.

BACKGROUND Few reports are available on the characteristics of electrical storms of ventricular tachycardia (VT storm) refractory to intravenous (IV) amiodarone. METHODSANDRESULTS IV-amiodarone was administered to 60 patients with ventricular tachyarrhythmia between 2007 and 2012. VT storms, defined as 3 or more episodes of VT within 24 h, occurred in 30 patients (68±12 years, 7 female), with 12 having ischemic and 18 non-ischemic heart disease. We compared the clinical and electrocardiographic characteristics of the patients with VT storms suppressed by IV-amiodarone (Effective group) to those of patients not affected by the treatment (Refractory group). IV-amiodarone could not control recurrence of VT in 9 patients (30%). The Refractory group comprised 5 patients with acute myocardial infarctions. Although there was no difference in the VT cycle length, the QRS duration of both the VT and premature ventricular contractions (PVCs) followed by VT was narrower in the Refractory group than in the Effective group (140±30 vs. 178±25 ms, P<0.01; 121±14 vs. 179±22 ms, P<0.01). In the Refractory group, additional administration of IV-mexiletine and/or Purkinje potential-guided catheter ablation was effective. CONCLUSIONS IV-amiodarone-refractory VT exhibited a relatively narrow QRS tachycardia. The narrow triggering PVCs, suggesting a Purkinje fiber origin, may be treated by additional IV-mexiletine and endocardial catheter ablation.

Left ventricular stiffness estimated by diastolic wall strain is associated with paroxysmal atrial fibrillation in structurally normal hearts

Left ventricular (LV) diastolic dysfunction depends on an impaired relaxation and stiffness. Abnormal LV relaxation contributes to the development of atrial fibrillation (AF), but the role of LV stiffness in AF remains unclear.

Frequency analysis of surface electrocardiograms (ECGs) in patients with persistent atrial fibrillation: Correlation with the intracardiac ECGs and implications for radiofrequency catheter ablation

The nature and significance of the frequency characteristics of the surface electrocardiogram (ECG) in patients with persistent atrial fibrillation (AF) undergoing radiofrequency ablation are unclear.

Detection and Evaluation of Pulmonary Hypertension by a Synthesized Right-Sided Chest Electrocardiogram.

BACKGROUND Current standard 12-lead electrocardiogram (ECG) criteria for diagnosing pulmonary hypertension (PH) have a low sensitivity. Although the right-sided chest ECG (V3R-V5R) increases the diagnostic accuracy, these additional leads are not routinely recorded. The aim of the present study was to assess the usefulness of the synthesized right-sided chest ECG (Syn-ECG), generated from 12-lead ECG information, in the detection and evaluation of PH. PATIENTS AND METHODS The Syn-ECG waveforms in 30 patients with PH, defined as an estimated pulmonary arterial systolic pressure (PASP) >35 mmHg, were compared to those in 30 age- and gender-matched normal subjects. RESULTS The R wave amplitude and R/S ratio in the Syn-ECGs were significantly (P<0.01) greater in patients with PH than in the controls. The R wave amplitude in the Syn-ECGs exhibited a significant and better correlation (correlation coefficient 0.513-0.596, P<0.001) with the PASP than lead V1 (correlation coefficient 0.375, P=0.02). A receiver-operating characteristic curve analysis showed that the R wave amplitude (AUC 0.802, P<0.001) and R/S ratio (AUC 0.823, P<0.001) in the synthesized V5R was a good predictor of PH. New criteria, including 1) an R in V5R>0.12 mV, and 2) R/S ratio in V5R>0.42, had an improved sensitivity (0.63 and 0.73, respectively) and comparable specificity (0.93 and 0.87, respectively) to the conventional criteria (sensitivity 0.10-0.43, specificity 0.90-1.00). CONCLUSION The diagnostic criteria derived from the Syn-ECG provided better diagnostic accuracy than the known conventional criteria from the standard 12-lead ECG. This technique described in the present study may be useful for diagnosing and evaluating PH.

Electrophysiological characteristics of a left atrial anomalous muscular band in a case with paroxysmal atrial fibrillation

Anomalous fibromuscular bands located in the left ventricle or the right atrium have been demonstrated by echocardiography and are reported to have a relationship with specific types of tachycardias. Although a left atrial (LA) anomalous band is found in approximately 2% of the cases by necropsy, it is rare to be diagnosed clinically. Therefore, its clinical significance, particularly in the development of atrial fibrillation (AF), is unclear. Furthermore, the electrophysiological characteristics have not been revealed. We experienced a case with a prominent anomalous band in the LA in a patient with paroxysmal AF in whom catheter ablation was performed. During the ablation session, we assessed its electrophysiological characteristics.

Peri-coronary sinus atrial flutter associated with prior slow pathway ablation

Introduction A human anatomic study has shown that a cuff of striated muscle consistently surrounds the venous wall of the coronary sinus (CS) and is connected to the left atrium (LA) by muscular bundles in a variable fashion. The presence of electrical connections between the CS musculature and LA myocardium provides a potential anatomic substrate for reentry. In fact, atypical atrial flutter (AFL) involving the CS musculature in its reentrant circuits has been reported, and some studies have suggested that reentry via the CS–LA electrical connections could contribute to the initiation and maintenance of atrial fibrillation.