Beneficial effects of losartan for prevention of paroxysmal atrial fibrillation in patients with sick sinus syndrome: analysis with memory function of pacemaker.

Renin-angiotensin system (RAS) inhibitors may be useful in preventing the occurrence of paroxysmal atrial fibrillation (PAF). However, evaluation of such effect is difficult because many PAF episodes are asymptomatic and not all episodes are detected by intermittent electrocardiographic monitoring. A pacemaker has been developed with dedicated functions for AF detection and electrocardiogram storage. Accordingly, we examined the effect of losartan, an angiotensin receptor blocker on PAF occurrence using this new modality. We enrolled 70 consecutive patients who had undergone dual-chamber pacemaker implantation for sick sinus syndrome. Finally, 62 patients participated in the study. Thirty patients were randomized to the losartan group (mean 43 ± 12 mg/day) and 32 patients to the control group. They were followed up for 3 months. The frequency, the maximum duration and the total duration of PAF recorded by the stored electrocardiograms for the last 1 month during the observation period and study period were compared between the two groups. The change in the frequency of PAF from the observation period in the losartan and control groups was similar (-35 ± 25 vs. -67 ± 62 times; NS). However, the change in the maximum duration and the total duration of PAF was significantly shorter in the losartan group than in the control group (-493 ± 158 vs. -10 ± 69 min; p < 0.05, and -4007 ± 2334 vs. 1119 ± 714 min; p < 0.05, respectively). Losartan suppressed the maximum duration and the total duration of PAF in patients with sick sinus syndrome without hemodynamic changes. This is the first study to show the effect of a renin-angiotensin system inhibitor on the secondary prevention of PAF using the dedicated functions of a pacemaker for PAF detection and electrocardiogram storage.

Ethanol Ablation of Refractory Premature Ventricular Complex Originating from a Left Ventricular Summit Communicating Vein after Radiofrequency Catheter Ablation Failed in a Dilated Cardiomyopathy Patient.

During follow-up of a 60-year-old patient with dilated cardiomyopathy, a Holter electrocardiogram revealed monomorphic premature ventricular complexes (PVCs) accounting for 21-30% of total beats. Oral beta-blockers led to no improvement in PVC burden. The first radiofrequency catheter ablation attempt identified the PVC arising from the left ventricle summit communicating vein (CV) but failed to eliminate the PVC's origin. The second ablation attempt with selective infusions of 100% ethanol into the summit CV resulted in immediate termination of PVCs. The post-ablation course was uneventful. Echocardiography showed an improved ejection fraction, and a repeated Holter electrocardiogram showed no recurrence of PVCs during follow-up. Ethics The RCVEA procedures were approved by the Takagi Hospital Ethical Committee and were performed under an institutional review board-approved protocol. (Kouhou-kai Ethical Committee, ID: KR168) Fundings This work was supported by the Takagi Hospital Cardiology Research Grant. The authors declare no competing interests. Acknowledgements: We thank the patient, the patient's family, and the medical staff of Takagi Hospital for their valuable cooperation and kind support. Consent Written informed consent was obtained from the patient for the publication of this case report and accompanying images.

How to avoid development of AV block during RF ablation: anatomical and electrophysiological analyses at the time of AV node ablation.

BACKGROUND: With an aim to identify risk factors that can serve for prevention of atrioventricular (AV) block (AVB) during radiofrequency (RF) ablation, we conducted anatomical and electrophysiological investigations at the time of AV node ablation (AVNA). METHODS AND RESULTS: Ten patients who underwent AVNA were enrolled. RF energy was delivered from posterior region of septal annulus of the tricuspid valve to the His bundle potential (HBP) recording site using a stepwise approach. In each delivery, atrial/ventricle potential amplitude ratio (A/V ratio), HBP, and juctional ectopy (JE) that appeared during RF delivery were evaluated. Furthermore, fluoroscopic distance between ablation site and HBP recording site (anatomical H-ABL distance) and electrophysiological H-ABL interval were measured. HBP was recorded in 25 of total 70 RF deliveries. When HBP was recorded, the A/V ratio was significantly greater in the group with AVB than without AVB (1.6 ± 2.3 mV vs 0.1 ± 0.2 mV, P = 0.02). The minimum cycle length (CL) of JE was significantly shorter in the group with AVB than without AVB (438 ± 112 ms vs 557 ± 178, ms, P = 0.04). AVB developed frequently when H-ABL distance was less than 15 mm from right anterior oblique view 30° and 12 mm from left anterior oblique view 45° and when H-ABL interval was less than 10 ms. AVB did not develop over the above values. CONCLUSIONS: HBP with high A/V ratio, JE with short CL, short H-ABL distance, and short H-ABL interval of less than 10 ms should be avoided to prevent AVB during RF ablation at the near site of AV node.

Long-term results of the maze procedure on left ventricular function for persistent atrial fibrillation associated with mitral valve disease.

Although the maze procedure is often performed as a surgical treatment for atrial fibrillation (AF) combined with mitral valve surgery, the long-term efficacy of the maze procedure concerning cardiac function has not been determined. The aim of this study was to assess long-term results of the maze procedure for left ventricular function in patients with persistent AF associated with mitral valve disease. We analyzed 38 patients who underwent the maze procedure for persistent AF and mitral valve surgery. The cardiothoracic ratio on chest X-ray and the left atrial dimension, left ventricular end-diastolic dimension, left ventricular end-systolic dimension and left ventricular ejection fraction on transthoracic echocardiography were evaluated before and 6 years after the maze procedure. Twenty-two patients maintained sinus rhythm (SR group) and 16 patients had recurrence of permanent AF (AF group) after the maze procedure. Preoperative cardiac function and the methods of mitral surgery were similar between the two groups. At the latest follow-up, left ventricular function tended to be better in the SR group than in the AF group. Cardiovascular events occurred more often in the AF group during follow-up (50 vs. 18%, p < 0.05). This retrospective study revealed that maintaining the sinus rhythm after the maze procedure for patients who underwent mitral valve surgery might be important for preserving better long-term left ventricular function and result in fewer cardiovascular events.

Atrioventricular nodal ablation versus antiarrhythmic drugs after permanent pacemaker implantation for bradycardia-tachycardia syndrome.

Patients often require antiarrhythmic drugs to control tachycardia after permanent pacemaker implantation (PMI) for bradycardia-tachycardia syndrome. We compared atrioventricular nodal ablation (AVNA) to antiarrhythmic drugs after PMI for bradycardia-tachycardia syndrome. Twenty-eight symptomatic patients with bradycardia-tachycardia syndrome, all of which had a long pause after termination of paroxysmal atrial fibrillation, underwent PMI with RV lead placement at the mid-septum site. Among these patients, 14 underwent PMI and AVNA (AVNA group). The remaining 14 patients underwent PMI only, and continued to take anti-arrhythmic drugs (drug group). We compared cardiac function (cardio-thoracic ratio on chest X-ray, left atrial diameter, left ventricular end-diastolic dimension, and left ventricular-ejection fraction by echocardiography), exercise tolerance (6-min walking distance), symptoms, and the number of antiarrhythmic drugs just before and 6 months after PMI. Baseline characteristics were similar between the two groups, except for the number of antiarrhythmic drugs. Six months after PMI, cardiac function, exercise tolerance, and symptoms did not differ significantly between the two groups. Compared to the drug group (p < 0.01), the number of antiarrhythmic drugs was significantly smaller in the AVNA group 6 months after PMI. Patients who underwent AVNA concurrently with PMI with RV lead placement at the mid-septum site for bradycardia-tachycardia syndrome were able to reduce the intake of drugs and improve their tachycardia-related symptoms while maintaining cardiac function and exercise tolerance.

Chronic cardiac resynchronization therapy reverses cardiac remodelling and improves invasive haemodynamics of patients with severe heart failure on optimal medical treatment.

AIMS: The aim of this study was to assess chronic invasive haemodynamic effects of cardiac resynchronization therapy (CRT) in patients with severe heart failure. METHODS AND RESULTS: Seventeen patients with New York Heart Association (NYHA) class III or IV and QRS duration >120 ms on optimal treatments underwent CRT. Haemodynamic data were obtained by cardiac catheterization before and 1 month after CRT. Clinical parameters and exercise tolerance were also evaluated. Chronic CRT improved haemodynamics significantly; mean pulmonary capillary wedge pressure decreased from 15.9 +/- 6.1 to 10.2 +/- 5.3 mmHg (P < 0.05), systolic pulmonary artery pressure decreased from 36.5 +/- 13.2 to 26.7 +/- 11.9 mmHg (P < 0.05), left ventricular end-diastolic pressure decreased from 15.6 +/- 7.2 to 10.5 +/- 7.3 mmHg (P < 0.05), end-diastolic volume decreased from 358.8 +/- 84.6 to 322.9 +/- 99.0 mL (P < 0.05), end-systolic volume decreased from 264.1 +/- 67.6 to 219.2 +/- 74.3 mL (P < 0.05), left ventricular ejection fraction increased from 25.4 +/- 6.2 to 33.1 +/- 4.9% (P < 0.05), and cardiac index increased from 1.9 +/- 0.4 to 2.2 +/- 0.5 L/min/m(2) (P < 0.05). Chronic CRT significantly improved functional capacity such as NYHA classification, 6 min walk distance, and peak oxygen uptake. CONCLUSION: Chronic CRT improved not only symptoms and exercise tolerance but also invasive haemodynamics associated with reversed cardiac remodelling.

Detection of coronary artery stenosis after successful percutaneous coronary intervention by dipyridamole stress portable type signal-averaged electrocardiography: a prospective study.

In our previous studies, using portable type signalaveraged electrocardiography (portable SAECG) with dipyridamole stress we reported that patients with coronary artery disease were identified at the bedside with high sensitivity and specificity. In this study we prospectively investigated whether coronary artery stenosis after successful percutaneous coronary intervention (PCI) could be detected. Standard 12-lead QRS wave SAECG was performed before and after dipyridamole stress at the bedside in 61 patients 8.0 +/- 9.4 months after successful PCI for myocardial infarction or angina pectoris (46 males and 15 females, mean age 66 +/- 12 years). The filtered QRS duration (fQRSd) before and after dipyridamole stress was determined by the multiphasic oscillation method at each lead of the standard 12 leads, and the maximal value of changes in fQRSd (MAX DeltafQRSd) among the 12 leads was determined. The positive test was defined as MAX DeltafQRSd > or =5 ms, and negative as MAX DeltafQRSd <5 ms based on our previous studies. Then selective coronary arteriography was performed. In the positive group (n = 24), 21 patients had stenosis (> or =50%) of the coronary artery and 3 did not. In the negative group (n = 37), 8 patients had stenosis and 29 did not. The sensitivity, specificity, positive predictive accuracy, and negative predictive accuracy for the detection of coronary artery stenosis by SAECG were 72%, 91%, 88%, and 78%, respectively. Dipyridamole stress portable SAECG is useful to detect patients with coronary artery stenosis after successful PCI.

Implantation of pacemaker for sick sinus syndrome in a patient with persistent left superior vena cava and absent right superior vena cava.

Absent right superior vena cava with persistent left superior vena cava in normal situs is an exceedingly rare congenital anomaly. In such cases, pacemaker implantation (PMI) is very difficult or even impossible. We report the case of a patient with sick sinus syndrome in whom PMI was easily performed via the left superior vena cava by using a steerable stylet.

Portable-type signal-averaged electrocardiography with dipyridamole to detect patients with coronary artery disease.

BACKGROUND: In a retrospective study portable-type signal-averaged electrocardiography (SAECG) with dipyridamole stress was found to identify patients with coronary artery disease (CAD) at their bedside with high sensitivity and specificity, so the utility of this method was prospectively investigated in the present study. METHODS AND RESULTS: Standard 12-lead QRS wave SAECG was performed before and after dipyridamole stress at the bedside in 71 patients with chest pain (43 males, mean age 63 +/-9 years). The filtered QRS duration (fQRSd) before and after dipyridamole stress was determined by multiphasic oscillation method for each of the standard 12 leads, and the maximal value of changes in fQRSd (MAX DeltafQRSd) among the 12 leads was determined. The positive test was defined as MAX DeltafQRSd >or=5 ms, and negative as MAX DeltafQRSd <5 ms based on the previous study. Selective coronary arteriography was performed next. In the positive group (n=31), 25 patients had significant stenosis of the coronary artery and 6 did not. In the negative group (n=40), 5 patients had significant stenosis and 35 did not. The sensitivity, specificity, positive predictive accuracy and negative predictive accuracy for CAD detection by SAECG was 83%, 85%, 81% and 88%, respectively. CONCLUSIONS: Dipyridamole-stress portable SAECG is useful for detecting CAD at the patient's bedside with high sensitivity and specificity.

P wave signal-averaged electrocardiography predicts recurrence of paroxysmal atrial fibrillation in patients with Wolff-Parkinson-White syndrome who underwent successful catheter ablation: a prospective study.

INTRODUCTION: Paroxysmal atrial fibrillation (PAF) frequently occurs in patients with Wolff-Parkinson-White (WPW) syndrome. Catheter ablation of the accessory pathway eliminates PAF in some patients, but PAF frequently recurs in other patients. The present study was designed to determine prospectively whether P wave signal-averaged electrocardiography (P-SAECG) predicts the recurrence of PAF after successful ablation in patients with WPW syndrome. METHODS AND RESULTS: Forty-six patients with WPW syndrome who had episodes of PAF were prospectively followed. SAECG recording was performed on day 7 after successful ablation of the accessory pathway at study entry. Abnormal P-SAECG for the prediction of recurrence of PAF was defined as a filtered P wave duration > 130 msec. Eleven patients had an abnormal P-SAECG (group 1), whereas 35 patients (group 2) did not. The two groups did not differ in terms of gender, age, left atrial dimension, and atrial vulnerability as determined by electrophysiologic study. During follow-up (40 +/- 19 months), the recurrence of PAF was noted in 10 (91%) of 11 patients in group 1, whereas it was observed in only 2 (6%) of 35 patients in group 2. Kaplan-Meier analysis revealed that the recurrence of PAF was significantly more frequent in group 1 than in group 2 (log rank test, P < 0.0001). By multivariate analysis, filtered P wave duration >130 msec was an independent predictor of recurrence of PAF after ablation (Chi-square = 21.5, P < 0.0001). CONCLUSION: The results of this study indicate that P-SAECG may be useful for identifying patients at risk for recurrence of PAF after successful ablation of WPW syndrome.