Does impaired respiratory function lead to sudden cardiac death?

• Published in: Thorax Vol. 77; no. 7; pp. 641 - 642
• Main Authors: D'Cruz, Rebecca F, Kaltsakas, Georgios
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and British Thoracic Society 01.07.2022; BMJ Publishing Group LTD
• Subjects: Asthma; Cardiovascular disease; Chronic obstructive pulmonary disease; clinical epidemiology; COPD; COVID-19; Editorial; Lung function; Mortality; respiratory physiology; Sudden cardiac death; asthma; Lung function; Sudden cardiac death; respiratory physiology; clinical epidemiology; COPD
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thoraxjnl-2021-218296

Among asthmatic children and young adults (<35 years) who died suddenly in a Danish cohort, SCD was listed as the cause of death in two-thirds, with fatal asthma attack accounting for the remaining third.4 Cheng et al. provide valuable insights into possible risk factors for SCD as well as spirometry data (although without reversibility testing) in a large cohort using data from four North American communities spanning two and a half decades.5 Of the population of nearly 15 000 patients, patients in the lowest forced expiratory volume in 1 second (FEV1) quintile had an FEV1 of 75% predicted and 44% exhibited an obstructive FEV1/FVC (forced vital capacity). The risk of acute cardiovascular events is further increased during the 90 days following an acute exacerbation.7 Large observational datasets have demonstrated that patients with an established diagnosis of COPD are at increased risk of SCD, independent of medications, electrocardiographic risk markers and left ventricular ejection fraction.8 9 Furthermore, data from Kurl et al. collected from patients without a diagnosis of obstructive airways disease over 20 years demonstrated an 18% reduction in SCD risk with every 10% increase in predicted FEV1, which the current data are consistent with.10 Mechanisms underpinning this relationship remain speculative, with proarrhythmogenic right ventricular remodelling, systemic inflammation, arterial stiffness and hypoxia-related altered cardiac repolarisation all warranting further evaluation.9 Pharmacological interventions used in both asthma and COPD to reduce exacerbation frequency may also confer cardiovascular risk, particular of induction of cardiac arrythmias, for example, through long-term theophylline and macrolide antibiotic usage. Diurnal, Weekly and seasonal variation of sudden death. population-based analysis of 24,061 consecutive cases.