QTc Interval Prolongation and Life-Threatening Arrhythmias During Hospitalization in Patients With Coronavirus Disease 2019 (COVID-19): Results From a Multicenter Prospective Registry.

BACKGROUND: Prolonged QTc intervals and life-threatening arrhythmias (LTA) are potential drug-induced complications previously reported with antimalarials, antivirals, and antibiotics. Our objective was to evaluate the prevalence and predictors of QTc interval prolongation and incidences of LTA during hospitalization for coronavirus disease 2019 (COVID-19) among patients with normal admission QTc. METHODS: We enrolled 110 consecutive patients in a multicenter international registry. A 12-lead electrocardiograph was performed at admission, after 7, and at 14 days; QTc values were analyzed. RESULTS: After 7 days, 15 (14%) patients developed a prolonged QTc (pQTc; mean QTc increase 66 ± 20 msec; +16%; P < .001); these patients were older and had higher basal heart rates, higher rates of paroxysmal atrial fibrillation, and lower platelet counts. The QTc increase was inversely proportional to the baseline QTc level and leukocyte count and directly proportional to the basal heart rate (P < .01).We conducted a multivariate stepwise analysis including age, male gender, paroxysmal atrial fibrillation, basal QTc values, basal heart rate, and dual antiviral therapy; age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.00-1.13; P < .05), basal heart rate (OR, 1.07; 95% CI, 1.02-1.13; P < .01), and dual antiviral therapy (OR, 12.46; 95% CI, 2.09-74.20; P < .1) were independent predictors of QT prolongation.The incidence rate of LTA during hospitalization was 3.6%. There was 1 patient who experienced cardiac arrest and 3 with nonsustained ventricular tachycardia. LTAs were recorded after a median of 9 days from hospitalization and were associated with 50% of the mortality rate. CONCLUSIONS: After 7 days of hospitalization, 14% of patients with COVID-19 developed pQTc; age, basal heart rate, and dual antiviral therapy were found to be independent predictors of pQTc. Life-threatening arrhythmias have an incidence rate of 3.6%, and were associated with a poor outcome.

Predictive value of very low frequency at spectral analysis among patients with unexplained syncope assessed by head-up tilt testing.

BACKGROUND: The role of heart rate variability (HRV) in the prediction of vasovagal syncope during head-up tilt testing (HUTt) is unclear. AIM: To evaluate the ability of the spectral components of HRV at rest to predict vasovagal syncope among patients with unexplained syncope referred for HUTt. METHODS: Twenty-six consecutive patients with unexplained syncope were enrolled in the study. All patients underwent HRV evaluation at rest (very low frequency [VLF], low frequency [LF], high frequency [HF] and LF/HF ratio) and during HUTt. HUTt was performed using the Westminster protocol. Continuous electrocardiogram and blood pressure monitoring were performed throughout the test. RESULTS: Eight (31%) patients developed syncope during HUTt. There were no baseline differences in terms of clinical features and HRV variables among patients who developed syncope and those who did not, except for VLF (2421 vs 896ms2; P<0.001). In the multivariable logistic regression analysis, including age and sex, VLF was the only independent variable associated with syncope during HUTt (odds ratio 1.002, 95% confidence interval 1.0003-1.0032; P=0.02). The area under the curve at rest was 0.889 for VLF, 0.674 for HF and 0.611 for LF. A value of VLF>2048ms2 was the optimal cut-off to predict syncope during HUTt (sensitivity 87.5%, specificity 72.2%). CONCLUSIONS: VLF at rest predicted the incidence of syncope during HUTt. Further studies are warranted to confirm these preliminary data.

Left ventricular rupture in an anterior wall acute myocardial infarction with severe intra-ventricular gradient.

We report the case of a 72-year-old man with ST-elevation acute myocardial infarction and severe intra-ventricular gradient (>40 mmHg), who died with left ventricular rupture (LVR). We postulate that severe intra-ventricular gradient detectable at admission may be related to subsequent LVR and proposed as a risk factor for LVR.