Long-term effectiveness of right septal pacing vs. right apical pacing in patients with atrioventricular block

AbstractBackgroundLong-term right ventricular apical (RVA) pacing increases the risk of heart failure (HF) by inducing ventricular dyssynchronization. Although recent studies suggest that right ventricular septal (RVS) pacing results in improved short-term outcomes, its long-term effectiveness remains unclear.Methods and resultsThis study investigated 149 consecutive patients who underwent implantation of a dual chamber pacemaker for atrioventricular block with either RVS-pacing between July 2007 and June 2010 or RVA-pacing between January 2003 and June 2007. The endpoint was defined as death and hospitalization due to heart failure (HF). The rates of mortality and hospitalization due to HF were significantly lower in the RVS-pacing group than that in the RVA-pacing group (event free RVS: 1 year, 98% and 2 years, 98%; RVA: 1 year, 85% and 2 years, 81%; p<0.05). None of the patients died from HF in the RVS-pacing group, while 4 patients died from HF in the RVA-pacing group within 2 years after pacemaker implantation. The paced QRS interval was significantly shorter with RVS pacing than with RVA pacing at different times after pacemaker implantation (RVS: immediately 157.8±24.0ms, after 3 months 157.3±17.5ms, after 6 months 153.6±21.7ms, after 12 months 153.6±19.4ms, after 24 months 149.3±24.0ms vs. RVA: immediately 168.3±23.7ms, after 3 months 168.7±26.0ms, after 6 months 168.0±22.8ms, after 12 months 171.2±22.3ms, after 24 months 176.1±25.5ms; p<0.05).ConclusionsRVS pacing is feasible and safe with more favorable clinical benefits than RVA pacing

Effect of Implantable Cardioverter-defibrillator Therapy for Ventricular Fibrillation Patients with Out-of-hospital Cardiac Arrest

Survivors of ventricular fibrillation out-of-hospital cardiac arrest（VF-OHCA）due to potentially reversible causes such as acute coronary syndrome（ACS）, vasospastic angina and electrolyte abnormalities are considered low risk for recurrent arrhythmia. Accordingly, implantable cardioverter-defibrillator therapy is not routinely recommended in such patients. We investigated the risk of mortality and the value of ICD therapy for VF-OHCA. Among 2,248 cardiopulmonary arrest patients presenting at our hospital, we retrospectively investigated 110 patients with VF-OHCA who were admitted for treatment. We divided the patients based on ICD（n＝71） or No-ICD status（n＝39）, and on reversible cause（n＝70） or irreversible cause（n＝40）. The groups were compared for baseline characteristics, mortality and ICD therapies. Patients with a reversible cause had a significantly lower rate of ICD implantation than those with an irreversible cause（P＝0.03）. Males in the ICD group presented more frequently than those in the No-ICD group, and cardiac mortality in patients with acute coronary syndrome was significantly lower with ICD therapy than without ICD（P＝0.04）. The rate of appropriate ICD therapies with a reversible cause was 28％, and the first ICD therapy was highest within 1 year post-implantation. Patients with VF-OHCA due to a reversible cause remain at high risk of recurrent ventricular arrhythmias, suggesting that ICD implantation is a reasonable approach in such cases

Head-up Tilt Test May Be Useful for Determining Permission of Flight for Regular Passenger Aircraft Pilots with Vasovagal Syncope

To determine the permissibility of piloting an aircraft with vasovagal syncope （VVS） is a complex responsibility, because it is difficult to evaluate VVS quantitatively. There are no clear guidelines for aircraft pilots with VVS. In some facilities, Head-up Tilt Test （HUTT） is used to determine its reproducibility and treatment effect. In most cases, permission is dependent on the strict examinations by specialists and judgement of the committee established for each country. Therefore, we assessed pilots with VVS and designed an algorism of permission for piloting an aircraft. Here, we describe 7 consecutive regular passenger aircraft pilots with VVS who were restricted to fly. All patients were men and their mean age was 37 years. All pilots were permitted to fly after at least two or more tilt-tests. The observation period was two years after flight permission. None of the pilots in the present study fainted after receiving flight permission. We can make a risk stratification to determine hypotensive susceptibility by multiple tilt tests. Based on the results of multiple HUTT, we can more quantitatively make the judgement as to whether the pilot’s VVS is well managed

Epicardial Adipose Tissue in the Right Atrium Is Associated with Progression of Atrial Fibrillation and Recurrence after Pulmonary Vein Catheter Ablation in Patients with Atrial Fibrillation

An increase in epicardial adipose tissue（EAT）in the left atrium（LA）predicts the progression of atrial fibrillation（AF）and AF recurrence after pulmonary vein catheter ablation（CA）. We hypothesized that EAT in the right atrium（RA）is also associated with the progression of AF and post-CA AF recurrence. Using 128-slice multidetector computed tomography, EAT volume and atrial volume were measured 3-dimensionally before CA in 68 patients who had proven AF（paroxysmal AF, 42; persistent AF, 26; mean age, 65±11 years; 42.6％ female）with successful CA and 21 volunteers with sinus rhythm（age, 63±13 years; 52.3％ female）. In both atria, EAT and atrial volumes were largest in patients with persistent AF, followed, in order, by those with paroxysmal AF, and then healthy volunteers（P＜0.001）. Increased EAT and atrial volumes in both atria predicted persistent AF（P＜0.001）. Fifteen patients had AF recurrence（22.1％）during the 2-year period after CA. Increased EAT volume in both atria were independent predictors for AF recurrence, and a RA EAT volume≥6.2ml was an independent predictor, with a hazard ratio of 5.47（95％ confidence interval, 1.2-24.3; P=0.03）. The combination of EAT and atrial volume in both atria was a more powerful independent prognostic factor, with a hazard ratio of 4.8（95％ confidence interval, 1.7-3.7; P=0.003）, and a sensitivity of 60％ in 9 of 15 patients, and specificity of 81.1％ in 43 of 53 patients,（P=0.003）. RA EAT is associated with the progression of AF and post-CA AF recurrence

Recurrence of Atrial Fibrillation within Three Months after Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation : Analysis Using an External Loop Recorder with Auto-trigger Function

Pulmonary vein isolation (PVI) via catheter ablation has been shown to be a highly effective option for patients with symptomatic paroxysmal atrial brillation (AF). The recurrence of AF within 3 months after PVI is not considered a failure of the ablation procedure because early recurrence of AF is not always associated with late recurrence. We examined the usefulness of an external loop recorder with auto-trigger function (ELR-AUTO) to detect AF following PVI to characterize early recurrence and determine the implication of AF within 3 months after PVI. The study included 53 consecutive patients with symptomatic paroxysmal AF (age, 61.6 ± 12.6 years ; 77％ male) who underwent PVI, and were fitted with an ELR-AUTO for 7 ± 2 days within 3 months after PVI. Of the 33 patients(62.2％) who did not have AF within the 3-month period, only 1 patient had AF recurrence at 12 months. Seven of 20 patients (35％) who experienced AF within 3 months had symptomatic AF recurrence at 12 months. The sensitivity, specificity, positive predictive value, and negative predictive value of early AF recurrence for late recurrence was 87.5％, 71.1％, 35.0％, and 96.9％, respectively. Thus, AF recurrence detected by ELR-AUTO within 3 months after PVI can predict late AF recurrence. Freedom from AF in the firrst 3 months following ablation significantly predicts long-term freedom from AF. An ELR-AUTO is useful for detecting symptomatic and asymptomatic AF

New Parameter to Predict Recurrence of Paroxysmal Atrial Fibrillation after Pulmonary Vein Isolation by the P-Wave Signal-Averaged Electrocardiogram

Noninvasive methods for predicting the recurrence of atrial fibrillation (AF) after initial pulmonary vein isolation (PVI) have not been well described. The aim of the present study was to evaluate the usefulness of the P-wave signal-averaged electrocardiogram (P-SAECG) in predicting the recurrence of AF after initial PVI. The P-SAECG was recorded before and after (within 1 week) the initial PVI session. The filtered P-wave duration (FPD) and root mean square voltage of the last 20ms of the filtered P-wave (LP20) were measured in 87 consecutive idiopathic AF patients (ejection fraction ≥50%, B-type natriuretic peptide ≤200pg/ml). During the follow-up period (12±7 months), 22 of 87 (25%) patients had recurrence of AF (11 with paroxysmal AF and 11 with persistent AF). In the group with recurrence of paroxysmal AF, the post-PVI FPD was significantly shorter and the post-PVI LP20 was significantly larger than in the non-recurrence group. Furthermore, the post-PVI LP20/FPD ratio was significantly higher in the group with paroxysmal AF recurrence than in the non-recurrence group (0.024±0.009 vs 0.015±0.007µV/ms, respectively; P0.015µV/ms than in those with a post-PVI LP20/FPD ≤0.015µV/ms. The optimal post-PVI LP20/FPD cut-off value of 0.015µV/ms had a sensitivity of 90% and a specificity of 60%. The data also suggest that the post-PVI LP20/FPD may be a new parameter for predicting successful PVI in patients with idiopathic paroxysmal AF after PVI

Effect of Cardiac Rehabilitation in Preventing Implantable Cardioverter Defibrillator Therapy in Patients with Reduced Left Ventricular Ejection Fraction

In patients with implantable cardioverter defibrillators(ICD)or cardiac resynchronization therapy defibrillators(CRT-D), appropriate and inappropriate shocks lead to a higher risk of mortality. Cardiac rehabilitation(CR)is an established therapy for patients with ischemic heart disease and/or congestive heart failure. However, it is unclear whether CR could reduce the need for device therapies. The purpose of the present study was to investigate whether CR reduces device therapies and mortality in patients with severe cardiac dysfunction and ICD or CRT-D. Of the 390 patients who were implanted with an ICD or CRT-D between 1998 and 2015, 222(178 men, 44 women)with a low ejection fraction(EF; <45%)were investigated in this present study. The study cohort was divided into two groups, the CR group(n=70)and the non-CR group (n=152), and baseline clinical characteristics of the two groups were compared. Furthermore, the number of all device therapies, appropriate therapies, inappropriate therapies, and mortality for 1 year after ICD or CRT-D implantation were compared. There were no significant differences in baseline characteristics between the CR and non-CR groups(e.g. age 68.5 vs 66.2 years[P=0.16]; EF 27.9% vs 29.7%[P=0.14]). Kaplan-Meier analysis revealed that all device therapy events and inappropriate therapy events were lower in the CR than non-CR group(P=0.01 and P=0.03, respectively). Appropriate therapy events and mortality did not differ significantly between the two groups(5.7% vs 13.1%[P=0.09]and 11.4% vs 17.0%[P=0.28], respectively). CR may have beneficial effects in preventing therapy events, especially inappropriate therapy, in patients with an ICD or CRT-D

Usefulness of Intracardiac Local Ventricular Electrogram to Predict Responders in Patients Undergoing Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) is a well-established, efficient strategy for medically-refractory congestive heart failure (HF) with ventricular conduction disturbances. However, about 30% of patients who undergo CRT do not receive any benefit. Therefore, we investigated the usefulness of the QRS-left ventricle (LV) interval for predicting responders during CRT implantation. This study included 66 patients who underwent CRT implantation. The definition of responder was a ≥15% reduction in LV end-systolic volume or ≥20% increase in LV ejection fraction. The QRS-LV interval was measured from the beginning of the body surface electrocardiogram QRS complex to the LV potential recorded by LV leads. We analyzed the correlations between the QRS-LV intervals and CRT responders, admission for HF and mortality. The patients were 67±12 years old, and their mean LV ejection fraction was 26.3%±8.3%. During follow-up (27.2±19.9 months), 27 patients were admitted for HF (40.1%), and 17 died (25.7%); the median QRS-LV interval was 103±33 msec. Patients were divided into 2 groups: wide QRS-LV (>103 msec), and narrow QRS-LV (<103 msec). The wide QRS-LV group had a lower mortality rate than the narrow QRS-LV group (77% vs. 53%, P<0.05). In patients with dilated cardiomyopathy, the QRS-LV interval was significantly wider in responders, compared to non-responders (112±9.2 vs. 80.0±10 msec, P<0.05). The QRS-LV interval did not correlate with CRT responders or admission for HF. The mortality rate was lower in patients with wide QRS-LV intervals, compared to narrow QRS-LV intervals. Furthermore, a wide QRS-LV interval might be a predictor for CRT responders in patients with dilated cardiomyopathy

Ordinary Autonomic Unbalance Can Reflect Diagnosis of Neurally Mediated Reflex Syncope

Background: In the present study we investigated autonomic dysfunction using hemodynamics and analysis of heart rate variability (HRV) following ambulatory blood pressure monitoring (APBM) in patients with neurally mediated reflex syncope (NMRS). In addition, we evaluated the usefulness of ABPM for diagnosing NMRS. Methods: In all, 88 consecutive patients with syncope and 12 controls (Group C) were subjected to a head-up tilt (HUT) test (80°, 30 min). If no syncope or presyncope occurred, the HUT test was repeated in the patient group following drug loading (ATP, isoproterenol, and/or isosorbide dinitrate). Results: Forty patients had a positive HUT test, with or without drug loading (Group P) ; the HUT test was negative in 48 patients, even after drug loading. Average daytime systolic and diastolic blood pressure (SBP and DBP, respectively) was significantly lower in Group P than in Group C (P = 0.042 and P = 0.047, respectively). The average standard deviation of SBP at night (SD-SBPNight) was significantly higher in Group P than in Group C (P = 0.004). HRV analysis revealed a significantly higher daytime high-frequency component in Group P than in Group C (P = 0.041). Conclusion: The results of the present study suggest that lower daytime blood pressure and a larger SD-SBPNight, as determined by ABPM, are associated with vagal nerve hyperactivity and sympathetic hypoactivity in patients with NMRS. Thus, an inadequate circadian rhythm in blood pressure variation, as identified by ABPM, may be useful for the diagnosis of NMRS