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Prognosis in cardiac pacing. A comparison between patients with atrioventricular block and sick sinus syndrome
Insights
Patients with atrioventricular (AV) block treated with pacemakers have a poorer prognosis, especially those with coronary heart disease (CHD). AV block indicates more widespread myocardial damage than sick sinus syndrome (SSS).
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Atrioventricular (AV) block and sick sinus syndrome (SSS) are common causes of bradycardia requiring pacemaker implantation.
- The long-term prognosis and mortality associated with these conditions, particularly in the presence of co-existing coronary heart disease (CHD), require further investigation.
Purpose of the Study:
- To compare the prognosis of patients with AV block versus SSS.
- To evaluate the impact of coronary heart disease (CHD) on mortality in patients with AV block and SSS.
Main Methods:
- Retrospective cohort study comparing 64 patients with AV block to 56 patients with SSS.
- Mean observation period of 32.5 months.
- Analysis included comparison of survival rates and mortality between groups, with subgroup analysis for patients with and without known CHD.
Main Results:
- Patients with AV block had a higher mortality rate compared to SSS, both in the overall cohort and within subgroups.
- Mortality was significantly higher in patients with known CHD compared to those with isolated conduction defects (ICD).
- Among patients with CHD, AV block carried a substantially higher mortality risk (58%) than SSS (24%).
- Regression analysis confirmed increased mortality for AV block versus SSS (p=0.02) and for males versus females (p=0.04).
- The excess mortality in patients with CHD versus ICD was significant (p=0.01).
Conclusions:
- AV block is associated with increased mortality, likely due to more extensive myocardial damage compared to SSS.
- The presence of CHD significantly exacerbates the poor prognosis in patients with AV block, indicating widespread myocardial damage.
Abstract:
The prognosis of 64 patients with atrioventricular (AV) block among 128 consecutive patients, 65 males and 63 females, treated with permanent pacemakers, was compared with that of 56 patients with sick sinus syndrome (SSS) during a mean observation period of 32.5 months. A poor survival rate was found in patients with known coronary heart disease (CHD) compared to those with isolated conduction defect (ICD). Among patients with CHD, a higher mortality was found in patients with AV block than in those with SSS (58 vs. 24%). Likewise, among patients with ICD the mortality in AV block was higher than in SSS (31 vs. 15%). Regression analysis showed a mortality excess in AV block vs. SSS (p=0.02), males vs. females (p=0.04). The mortality excess in patients with CHD vs. ICD was significant (p=0.01). It is concluded that the increased mortality rate in patients with AV block is related to widespread myocardial damage, this being especially pronounced in patients with CHD.