Among depressed patients on tricyclic antidepressants, second-degree atrioventricular block occurred in 9% of those with preexisting bundle-branch block versus 0.7% of those with normal ECGs.
Cohort (n=196)
Do tricyclic antidepressants at therapeutic concentrations increase the risk of cardiovascular complications in depressed patients with preexisting cardiac conduction disease compared to those with normal electrocardiograms?
Tricyclic antidepressants at therapeutic doses pose a significantly higher risk of second-degree AV block in depressed patients with preexisting bundle-branch block compared to those with normal ECGs.
Absolute Event Rate: 9% vs 0.7%
The observation that fatalities from tricyclic antidepressant (TCA) overdose are associated with heart block and/or arrhythmias has led to concern about the cardiovascular effects of TCAs. Contrary to expectations, studies have shown TCAs to be relatively safe in patients without heart disease. However, it is unclear whether these drugs are also safe in patients with heart disease. This prospective study compared the risk of cardiovascular complication at therapeutic plasma concentrations of TCAs in 196 depressed patients, 155 with normal electrocardiograms and 41 with either prolonged PR interval and/or bundle-branch block. The prevalence of second-degree atrioventricular block was significantly greater in patients with preexisting bundle-branch block (9%) than in patients with normal electrocardiograms (0.7%). Orthostatic hypotension occurred significantly more frequently with imipramine than with nortriptyline, and in patients with heart disease.
Steven P. Roose (Sun,) conducted a cohort in Depression (n=196). Preexisting bundle-branch block and/or prolonged PR interval vs. Normal electrocardiograms was evaluated on Second-degree atrioventricular block. Among depressed patients on tricyclic antidepressants, second-degree atrioventricular block occurred in 9% of those with preexisting bundle-branch block versus 0.7% of those with normal ECGs.
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