Spectrum of cardiac manifestations and its relationship to outcomes in patients admitted with scrub typhus infection

AIM To study the spectrum of cardiac manifestations in scrub typhus infection and assess its relationship to outcomes.METHODS Demographic data, electrocardiographic(ECG) changes, left ventricular (LV) systolic and diastolic function, myocardial injury (defined as troponin T > 14 pg/mL), and pericardial effusion were documented. Myocarditis was diagnosed when myocardial injury was associated with global LV systolic dysfunction. The relationship between myocarditis and outcomes was assessed using logistic regression analysis and expressed as odds ratio(OR) with 95%CI.RESULTS The cohort(n = 81; 35 males) aged 49.4 ± 16.1 years(mean, SD) presented 8.1 ± 3.1 d after symptom onset. The APACHE-Ⅱ score was 15.7 ± 7.0. Fortyeight (59%) patients were ventilated, and 46 (56%) required vasoactive agents. Mortality was 9.9%. ECG changes were non-specific; sinus tachycardia was the most common finding. Myocardial injury was evident in 61.7% of patients and LV systolic dysfunction in 30.9%. A diagnosis of myocarditis was made in 12.3%. In addition, seven patients with regional wall motion abnormalities had LV systolic dysfunction and elevated cardiac enzymes. Mild diastolic dysfunction was observed in 18 (22%) patients. Mild to moderate pericardial effusion was seen in 51%. On multivariate logistic regression analysis, patients with myocarditis tended to be older (OR = 1.04, 95%CI: 0.99-1.09), had shorter symptom duration (OR = 0.69, 95%CI: 0.49-0.98), and tended to stay longer in hospital(OR = 1.17, 95%CI: 0.98-1.40). Myocarditis was not associated with increased mortality.CONCLUSION In scrub typhus infection, cardiac manifestations are frequent and associated with increased morbidity but not mortality.