Long-term follow-up of patients with drug-related atrioventricular block without a need of permanent pacemaker during index hospitalization.

BACKGROUND: Most of the patients hospitalized due to drug-related atrioventricular (AV) block do not require permanent pacemaker implantation (PPI) since AV block regresses following cessation of the responsible drug. However, AV block requiring PPI may relapse in long-term follow-up. In this study, we retrospectively evaluated the factors predicting the need for a PPI in the long-term follow-up in patients admitted to our hospital with drug-related AV block but did not require PPI in index hospitalization. RESULTS: We evaluated 177 patients who had been hospitalized with drug-related AV block between January 2012 and July 2020 and who had not required PPI during hospital follow-up. The patients were divided into two groups according to whether PPI was performed or not. The independent predictors of long-term PPI were evaluated and the effect of glomerular filtration rate (GFR) of the patients during the index hospitalization on the long-term outcome was compared. A GFR above 60 ml/min is an independent significant risk factor in predicting long-term permanent pacemaker implantation in drug-related AV blocks. It is found that the need for PPI was 2.64 times higher without adjusted and 1.9 times higher with adjusted for all covariates in patients with GFR above 60 ml/min during hospitalization compared to those with GFR below 30 ml/min. CONCLUSIONS: GFR may be considered as an indicator of the PPI need in patients with drug-related atrioventricular AV block.

Bradyarrhythmia development and permanent pacemaker implantation after cardiac surgery.

OBJECTIVE: Bradyarrhythmia is one of the complications that may develop after cardiac surgery. Only a few studies have previously dealt with this concern, and in our study, we investigated the factors affecting the development of atrioventricular block or sinus node dysfunction and the requirement of permanent pacemaker following cardiac surgery. METHODS: A total of 62 patients who developed the atrioventricular (AV) block or sinus node dysfunction and required a permanent pacemaker following cardiac surgery were included in the study. Among these, 31 patients were evaluated prospectively, and the information regarding 31 patients was evaluated retrospectively based on hospital records. Demographic, clinical, and surgical information was recorded. Patients were grouped according to the types of procedures, including the coronary artery bypass graft, valve surgery, congenital heart disease, and combinations of these. Patients were evaluated by standard 12-lead electrocardiogram and transthoracic echocardiography preoperatively. The postoperative development of bradyarrhythmia and requirement of permanent pacemaker were evaluated. RESULTS: The mean age of patients with preoperative conduction abnormality and wide QRS was statistically significantly higher than those without these disorders. The odds ratio for preoperative conduction abnormality risk in patients over 70 years of age was found as 4.429 (95% confidence interval, 1.40-13.93). There was no gender-related statistically significant difference in terms of left ventricular ejection fraction, left ventricular dilatation, interventricular septum thickness, the time interval from operation to the development of AV block, concomitant diseases, and complication rates. CONCLUSION: Preoperative conduction abnormality and wide QRS in patients over 70 years of age was determined as a risk factor.

Alzheimer's disease: is pacemaker implantation safe?

AIM: To evaluate the safety of pacemaker implantation in patients with Alzheimer's disease (AD). METHODS: We reviewed all cases admitted to our institution between January 2008 and June 2009, with symptomatic bradyarrhythmia for whom a permanent pacemaker was implanted. Beginning in June 2009, we prospectively collected data from all patients with the same diagnosis and procedure. Patients with a diagnosis of AD were included in the study. The risks and frequency of complications due to the pacemaker implantation were evaluated. Because of the older age of patients, they were divided into 2 groups to define the effect of age on complication rate. Group 1 consisted of patients aged <75 years, and group 2 consisted of those who are ≥75 years. RESULTS: Among the 574 patients with permanent pacemaker, 20 patients (3.4%) had a diagnosis of AD. Three patients with an AD experienced a complication and all were in group 2. However, the rate of complication was not significant within groups (P = 1.000). Reoperation was needed for all of them, and it was significantly higher in patients with AD than in patients without a concomitant disease (P = .006). Patients in group 2 had 3 times higher rate of complication (21.4%) than those without an AD and aged ≥75 years (7.1%; P = .125). CONCLUSION: Pacemaker implantation may be of risk in patients with AD, especially in those aged ≥75 years.

Circadian pattern of spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter defibrillators.

BACKGROUND: Previous studies have reported a circadian variation of ventricular tachyarrhythmias. However, there is no detailed information of the daily distribution of ventricular tachycardia (VT) and ventricular fibrillation (VF) episodes. The purpose of this study was to evaluate the daily distribution of episodes of ventricular tachyarrhythmia in patients with implantable cardioverter defibrillators. MATERIAL/METHODS: We used data stored by last-generation implantable cardioverter-defibrillators (ICD) to retrospectively evaluate the circadian distribution of VT and VF in 70 patients with ICD. The distribution of tachyarrhythmias was categorized into four time zones: zone 1 (06:00-11:59), zone 2 (12:00-17:59), zone 3 (18:00-23:59), and zone 4 (00:00-05:59). RESULTS: During a follow-up of a mean of 3.1+/-1.3 years, a total of 791 ventricular arrhythmias were recorded from which 631 events were VT and 160 VF. A circadian variation of episodes of ventricular tachyarrhythmia was evident. The incidence of ventricular arrhythmia sharply increased in zone 1 (8.82+/-2.13, p<0.0001). Episodes of VT had peaks in zones 1 and 2 (7.44+/-2.03 and 2.70+/-0.65, p<0.001) and episodes of VF had peaks in zones 1 and 4 (1.38+/-0.39 and 1.30+/-0.51, p<0.011). No difference was observed between patients who used betablocker and those who did not. CONCLUSIONS: Malignant ventricular tachyarrhythmias have a circadian distribution. VT peaks occur in the morning and noon hours and VF peaks occurs at the night and morning hours. Betablocker and/or amiodarone usage do not alter this distribution.