Heart Block First Degree Publications (1340)


Heart Block First Degree Publications


This study was conducted to assess the prevalence and characterization of CAD in high risk patients requiring pacemaker implantation for symptomatic bradyarrhythmias.
This study included 100 patients with symptomatic sinus node dysfunction or atrioventricular block, who were at high risk of CAD or had previously documented atherosclerotic vascular disease (ASCVD). Coronary angiography was performed before pacemaker implantation. Read More

CAD was defined as the presence of any degree of narrowing in at least one major coronary artery or its first order branch. Obstructive CAD was defined as ≥50% diameter stenosis. CAD was categorized as single vessel disease (SVD), double vessel disease (DVD), or triple vessel disease (TVD); and obstructive CAD in the arteries supplying the conduction system was sub-classified according to Mosseri's classification.
Out of 100 patients (mean age 64.6±10.7 years), 45 (45%) had CAD. 29% patients had obstructive CAD while 16% had non-obstructive CAD. 53.3% patients had SVD, 15.6% had DVD and 31.1% had TVD. Among patients with obstructive CAD; Type I, II, III and IV coronary anatomies were present in 6.9%, 34.5%, 10.3% and 48.3% patients respectively. Presence of CAD significantly correlated with dyslipidemia (p=0.047), history of smoking (p=0.025), and family history of CAD (p=0.002).
Angiographic CAD is observed in a substantial proportion of patients with symptomatic bradyarrhythmias and risk factors for CAD. It could be argued that such patients should undergo a coronary work-up before pacemaker implantation. Treatment of concomitant CAD is likely to improve the long term prognosis of these patients.

Acta Neurol. Scand.
Acta Neurol Scand 2017 Jan 8;135(1):129-133. Epub 2016 Mar 8.
Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.

Assessment of sinoatrial node function after Maze III procedure combined with a mitral valve operation.
100 patients were included in the research with persistent and long-standing persistent forms of atrial fibrillation (AF) and need of operative treatment concerning valve disease. The following preoperative preparation methods were executed to all patients: Electrocardiogram in 12 standard assignments;Two-dimensional echocardiographic with assessment of systolic and diastolic functions of the left ventricle, size of the left atrium and grade of valve disease;Transesophageal echocardiography for exclusion of blood clots in the left atrium and left atrial appendage;Coronary angiography for exclusion of coronary heart disease;Computer tomography for examination of cardiac chambers and anatomic characteristics of pulmonary veins. Read More

Electric cardioversion in X-ray operating room conditions was performed on all patients. After successful restoration of sinus rhythm, electrophysiological examination (EP) of heart was carried out. Then, on the first or second day after EP study, Maze III procedure combined with a mitral valve operation was performed.
Following the results of Maze III procedure combined with correction of valve disease, disposal of AF was observed in 95% of patients. 46% of patients had stable sinus rhythm to the moment of discharge from the hospital. 24% of patients had atrial rhythm with the maximum heart rate of 80-110 bpm (according to results of 24-hour Holter monitoring). For 25% of patients, it was necessary to implant a pacemaker. According to results of EP study, 13% of these patients suffered from sick sinus syndrome before operation. For 9% of the remaining 12% of patients, the indications for pacemaker implantation were atrioventricular nodal rhythm with low heart rate and pauses more than 3 sec long. For 1% of patients the indication was second degree AV block (type 2) and second degree SA block (type 2); for 1% the indication was complete heart block, and for 1% it was atrial rhythm and pauses more than 3 sec long. 13% of patients with an atrial rhythm and normal heart rate developed typical atrial flutter (AFL) in the early postoperative period. For all of them the RF catheter ablation with linear ablation of the right atrial isthmus and creation of isthmus block was effective, and further recurrence of AFL was not observed.
In the early postoperative period Maze III procedure combined with a mitral valve operation proved to be an effective surgical technique of treatment of persistent and long-standing persistent forms of AF. Only 12% of patients had dysfunction of sinus node work due to iatrogenesis.

Case Rep Cardiol
Case Rep Cardiol 2016 6;2016:5454160. Epub 2016 Nov 6.
Department of Medicine, Memorial Hospital of Rhode Island, Alpert Medical School, Brown University, Pawtucket, RI, USA.

Carditis is an uncommon presentation of the early disseminated phase of Lyme disease. We present the case of a young female who presented with erythema migrans and was found to have first-degree heart block which progressed to complete heart block within hours. After receiving ceftriaxone, there was complete resolution of the heart block in sequential fashion. Read More

Our case illustrates the importance of early recognition and anticipation of progressive cardiac conduction abnormalities in patients presenting with Lyme disease.

ESC Heart Fail
ESC Heart Fail 2016 Dec 4;3(4):288-292. Epub 2016 Jul 4.
Division of Cardiology and Cardiac Catheterization Laboratories Showa University Northern Yokohama Hospital Yokohama Japan.
Scand J Med Sci Sports
Scand J Med Sci Sports 2016 Nov 22;26(11):1283-1286. Epub 2015 Dec 22.
Department of Cardiology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia.

Cardiac arrhythmias are commonly reported in freedivers during maximal voluntary breath-holds, but their influence on the cardiological status and their long-term effects on the cardiac health of these athletes have not been investigated. Here we present the results of a study on 32 healthy young men (mean age 32.6 ± 1. Read More

3 years) who were divided into two groups of 16 subjects. One group included 16 continuously training freedivers at the "high achievers in sports" level (DIVERS group). The CONTROL group included 16 healthy young men not involved in sports. The subjects were monitored using 24-h electrocardiogram (ECG), and echocardiological study (EchoCG) for all the subjects was performed. The mean heart rate in the DIVERS group was 69.5 ± 1.7 bpm compared with 70.9 ± 1.5 bpm in the CONTROL group. The minimal heart rate was 42.3 ± 1.0 bpm in the DIVERS group and 48.8 ± 1.7 bpm in the CONTROL group (P < 0.005). The maximal heart rate was 132.8 ± 4.6 bpm in the DIVERS group and 132.1 ± 2.9 bpm in the CONTROL group. ECG analysis revealed supraventricular arrhythmias in the DIVERS group: four of the DIVERS (25%) exhibited supraventricular couplets and triplets, three (19%) exhibited transient first- and second-degree AV blocks (Mobitz type 1) at night, and one (6%) exhibited a second-degree sinoatrial block at night. According to the echocardiogram, the DIVERS had slightly larger left ventricles (5.1 ± 1.33, P < 0.05) and left atriums (41.1 ± 12.7) compared with the CONTROL group without exceeding the normal values. The right ventricle volume (3.6 ± 0.69, P < 0.05) was somewhat above the upper normal value (up to 3.5 cm). In conclusion, freediving athletes exhibited changes in their cardiac status, most likely due to the regular exercise, that were not associated with regular maximal voluntary breath-holds. These changes are within the normal physiological values and do not limit their freediving practice.

Clin Res Cardiol
Clin Res Cardiol 2016 Nov 18;105(11):944-952. Epub 2016 Jun 18.
Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, NY, USA.

In MADIT-CRT, patients with non-LBBB (right bundle branch block or nonspecific ventricular conduction delay) and a prolonged PR-interval derived significant clinical benefit from cardiac resynchronization therapy with defibrillator (CRT-D) compared to an implantable cardioverter defibrillator (ICD)-only. We aimed to study the long-term outcome of non-LBBB patients by baseline PR-interval with CRT-D versus ICD-only.
Non-LBBB patients (n = 534) were dichotomized based on baseline PR-interval: normal PR (PR < 230 ms), and markedly prolonged PR (PR ≥ 230 ms). Read More

The primary end point was heart failure (HF) or death. Secondary end points were HF only and all-cause death.
In patients with a prolonged PR-interval, CRT-D treatment related to a 67 % significant reduction in the risk of HF/death (HR = 0.33, 95 % CI 0.16-0.69, p = 0.003), 69 % decrease in HF (HR = 0.31, 95 % CI 0.14-0.68, p = 0.003), and 76 % reduction in the risk of death (HR = 0.24, 95 % CI 0.07-0.80, p = 0.020) compared to ICD-only (median follow-up 5.8 years). In normal PR-interval patients, CRT-D therapy was associated with a trend towards increased risk of HF/death (HR = 1.49, 95 % CI 0.98-2.25, p = 0.061), and significantly increased mortality (HR = 2.27, 95 % CI 1.16-4.44, p = 0.014). Significant statistical interaction with the PR-interval was demonstrated for all end points. Results were consistent for QRS 130-150 ms and QRS > 150 ms.
In MADIT-CRT, non-LBBB patients with a prolonged PR-interval derive sustained long-term clinical benefit with reductions in heart failure or death from CRT-D implantation, compared to an ICD-only. Our findings support implantation of CRT-D in non-LBBB patients with prolonged PR-interval irrespective of baseline QRS duration.

Int J Cardiovasc Imaging
Int J Cardiovasc Imaging 2016 Sep 15;32(9):1427-1438. Epub 2016 Jun 15.
Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Avenue, Room 411, New York, NY, USA.

Patients with left bundle branch block (LBBB) can exhibit mechanical dyssynchrony which may contribute to heart failure; such patients may benefit from cardiac resynchronization treatment (CRT). While cardiac magnetic resonance imaging (CMR) has become a common part of heart failure work-up, CMR features of mechanical dyssynchrony in patients with LBBB have not been well characterized. This study aims to investigate the potential of CMR to characterize mechanical features of LBBB. Read More

CMR examinations from 43 patients with LBBB on their electrocardiogram, but without significant focal structural abnormalities, and from 43 age- and gender-matched normal controls were retrospectively reviewed. The following mechanical features of LBBB were evaluated: septal flash (SF), apical rocking (AR), delayed aortic valve opening measured relative to both end-diastole (AVOED) and pulmonic valve opening (AVOPVO), delayed left-ventricular (LV) free-wall contraction, and curvatures of the septum and LV free-wall. Septal displacement curves were also generated, using feature-tracking techniques. The echocardiographic findings of LBBB were also reviewed in those subjects for whom they were available. LBBB was significantly associated with the presence of SF and AR; within the LBBB group, 79 % had SF and 65 % had AR. Delayed AVOED, AVOPVO, and delayed LV free-wall contraction were significantly associated with LBBB. AVOED and AVOPVO positively correlated with QRS duration and negatively correlated with ejection fraction. Hearts with electrocardiographic evidence of LBBB showed lower septal-to-LV free-wall curvature ratios at end-diastole compared to normal controls. CMR can be used to identify and evaluate mechanical dyssynchrony in patients with LBBB. None of the normal controls showed the mechanical features associated with LBBB. Moreover, not all patients with LBBB showed the same degree of mechanical dyssynchrony, which could have implications for CRT.

To investigate the clinical characteristics, prognoses, and presence of risk factors in young patients with Brugada syndrome (BS).
A consecutive cohort of 128 young BS patients (≤25 years old at diagnosis) was analysed. Eighty-eight patients (69%) were asymptomatic, whereas 40 (31%) presented with clinical manifestations of BS. Read More

Markers of prognosis and risk were identified upon comparison of these two groups. A history of malignant syncope was strong predictors of ventricular arrhythmic events. Family history of sudden cardiac death (SCD) and mutations in the SCN5A gene did not associate with increased risk. Symptomatic patients presented with significantly abnormal baseline electrical characteristics when compared with the asymptomatic cohort, including spontaneous type I electrocardiograph (ECG) patterns, sinus node dysfunction (SND), first-degree atrioventricular (AV) block, and intra-ventricular conduction delay. The symptomatic group more frequently exhibited atrial arrhythmias. Electrophysiological studies resulted positive more frequently in symptomatic patients, but no risk association for future events could be determined. During the follow-up period (mean: 65 months), 10 arrhythmic events occurred in nine symptomatic patients (event rate: 4.5% per year). No events occurred in the asymptomatic group. Variables significantly associated with arrhythmic events during follow-up were presence of symptoms at diagnosis and spontaneous type I ECG. The presence of atrial arrhythmias and conduction abnormalities was also associated with the risk of arrhythmic events during follow-up.
Symptomatic BS in the young age is a rare but malignant condition that can manifest with a spectrum of electrical abnormalities (i.e. SND, atrial tachycardias, AV block, and infra-nodal conduction delay) and result in the extreme cases in lethal arrhythmic events and SCD.

Ann. Thorac. Surg.
Ann Thorac Surg 2016 Oct 4. Epub 2016 Oct 4.
Division of Cardiac Surgery, Montreal Heart Institute, Montreal, Quebec, Canada. Electronic address:

Sutureless self-expandable aortic bioprostheses rely on radial forces for stabilization, raising concern that these devices may increase the risk of postoperative conduction disease. The purpose of this study was to determine the incidence of conduction disorders after sutureless aortic valve replacement (AVR) with the Perceval S (Sorin Group, Saluggia, Italy) bioprosthesis.
Between June 2011 and March 2013, 108 consecutive patients underwent sutureless AVR with the Perceval S prosthesis. Read More

Six patients (6%) had a permanent pacemaker (PPM) preoperatively and were excluded from the present study. Mean electrocardiographic follow-up was 14.6 ± 6.0 months.
Mean age was 79.2 ± 4.8 years (52% female). During the postoperative period, 34 patients (34%) had first-degree atrioventricular block, 2 (2%) had Mobitz-II atrioventricular block, and 16 (16%) had complete atrioventricular block. New-onset left bundle branch block and right bundle branch block were observed in 33 patients (33%) and 22 patients (22%), respectively. Inhospital postoperative PPM implantation was required in 23 patients (23%). Preoperative aortic valve area, age more than 85 years, and preoperative right bundle branch block were found to be independently associated with inhospital PPM implantation or new-onset postoperative conduction disorder. At follow-up, 3 more patients (3%) underwent PPM implantation. The cumulative incidences of PPM dependency and ventricular pacing more than 25% of the time were 18% ± 11% and 21% ± 10%, respectively, at 18 months.
In the present study, the postoperative PPM implantation rate (23%) after sutureless AVR with the Perceval S prosthesis was high. Surgical strategies aimed at mitigating this risk should be further investigated.