Sinus bradycardia in dengue: prevalence and clinical implications-an observational study

To estimate the frequency of sinus bradycardia in hospitalized adults with dengue, and assess its association with clinical outcomes.

This prospective observational study enrolled consecutive adults hospitalized with dengue at a tertiary hospital in Brazil. Patients with and without sinus bradycardia (heart rate <60 bpm) were compared. An exploratory post hoc analysis assessed the correlation between bradycardia onset and platelet recovery.

Among 33 patients, 12 developed sinus bradycardia (36.4%; 95% CI, 20.4%-54.9%). Baseline characteristics were similar except for lethargy, which was less frequent with bradycardia (8.3% vs 52.4%; P=.022). ICU admission did not differ significantly (16.7% vs 28.6%; risk ratio, 0.58; 95% CI, 0.14-2.45; P=.678). In 11 patients with complete temporal data, bradycardia onset correlated positively with platelet recovery (Spearman's ρ=0.61; 95% CI, 0.00-0.92; P=.048).

Sinus bradycardia was common in this small cohort, without a detected association with ICU admission. Its correlation with platelet recovery suggests possible occurrence during a later phase of dengue. Larger studies are needed.