ABSTRACT
BACKGROUND: Despite the advancement of electrocardiogram (ECG) monitoring methods, the most important factor influencing diagnostic yield (DY) may still be monitoring duration. Ambulatory ECG monitoring, typically with 24-48 hours duration, is widely used but may result in underdiagnosis of rare arrhythmias. AIMS: This study aimed to examine the relationship between the DY and monitoring duration in a large patient cohort and investigate sex and age differences in the presentation of arrhythmias. METHODS: The study population consisted of 25 151 patients (57.8% women; median [interquartile range, IQR], 71 [64-78] years), who were examined with mobile cardiac telemetry during 2017 in the United States, using the PocketECGTM that continuously transmits a signal on a beat-to-beat basis. We investigated the occurrence of atrial fibrillation at a burden of both ≤1% (atrial fibrillation [AF], ≤1%) and ≤10% (AF ≤10%), premature ventricular contractions (PVC; >10 000 per 24 hours), non-sustained ventricular tachycardias (nsVT), sustained ventricular tachycardias (VT ≥30 seconds), atrioventricular blocks (AVB), pauses of >3 seconds duration, and bradycardia (heart rate <40 beats per minute for ≥60 seconds). RESULTS: The median (IQR) recording duration was 15.4, 8.2-28.2) days. The DY increased gradually with monitoring duration for all types of investigated arrhythmias. Compared to DY after up to 30 days of monitoring, a standard 24 hours monitoring resulted in DY for males/females of 20%/18% for AF ≤1%, 29%/28% for AF ≤10%, 45%/40% for PVCs, 17%/11% for nsVT, 17%/11% for VT ≥30 seconds, 49%/42 for AVB, 27%/20% for pauses, 36%/29% for bradycardia. CONCLUSION: A substantial number of patients suffering from arrhythmias may remain undiagnosed due to insufficient ECG monitoring time.
Subject(s)
Atrial Fibrillation , Tachycardia, Ventricular , Ventricular Premature Complexes , Atrial Fibrillation/diagnosis , Atrial Fibrillation/epidemiology , Disclosure , Electrocardiography, Ambulatory , Female , Humans , Male , Tachycardia, Ventricular/diagnosis , Telemetry , United StatesABSTRACT
BACKGROUND: Heart rate control in atrial fibrillation (AF) is typically assessed by 24hour electrocardiography (ECG). There are scarce data on the use of 24hour ECG parameters to predict mortality in patients with AF. AIMS: We aimed to identify 24hour ECG parameters that predict mortality in patients with AF. METHODS: We enrolled 280 ambulatory patients (mean [SD] age, 72 [8.7] years; 57.9% men) with permanent or persistent AF. Data on mortality and pacemaker or defibrillator implantation during followup were collected. Predictors of mortality were assessed using the Cox proportional hazards model and C statistic. RESULTS: Compared with survivors, 78 patients (28%) who died were older, more often had comorbidities, left bundle branch block (LBBB), reduced left ventricular ejection fraction, lower maximum heart rate, higher number of ventricular extrasystoles, and the longest RR interval below 2 seconds. Univariate analysis showed higher mortality in patients with the longest RR intervals below 2 seconds compared with those with RR intervals of 2 seconds or longer (P <0.001). Independent mortality predictors in the regression model included older age, renal failure, history of coronary intervention, chronic obstructive pulmonary disease, LBBB, and a high number (≥770) or absence of RR intervals of at least 2 seconds. The area under the curve for mortality prediction increased after including ECG parameters (0.748; 95% CI, 0.686-0.81; vs 0.688; 95% CI, 0.618-0.758; P = 0.02). CONCLUSIONS: A high number of RR intervals longer than 2 seconds or their absence on 24hour ECG may predict mortality in patients with AF.