First-degree atrioventricular block in hypertrophic cardiomyopathy patients: an easy and worthy prognostic marker?

Area of Science:

• Cardiology
• Genetics
• Internal Medicine

Background:

• Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac condition.
• A link between first-degree atrioventricular block (FDAVB) and cardiovascular outcomes in HCM is suggested but not well understood.
• Investigating FDAVB's role in HCM pathophysiology and prognosis is crucial.

Purpose of the Study:

• To examine the association between FDAVB and clinical/imaging variables in HCM patients.
• To determine if FDAVB predicts cardiovascular events in HCM.
• To explore the relationship between FDAVB and echocardiographic parameters, specifically the E/e' ratio.

Main Methods:

• Retrospective study of 97 HCM patients in sinus rhythm (2000-2023).
• FDAVB defined as PR interval >200 ms.
• Analysis of clinical data, imaging variables, and cardiovascular events including atrial fibrillation (AF), heart failure hospitalizations, stroke, myocardial infarction, and defibrillator implantations.

Main Results:

• No significant association was found between FDAVB and the occurrence of cardiovascular events.
• Patients with FDAVB were older, more symptomatic (dyspnea), and had longer QRS duration.
• FDAVB was independently associated with a higher echocardiographic E/e' ratio (OR=1.588, p=0.039).

Conclusions:

• FDAVB does not appear to be a prognostic marker for major cardiovascular events in this HCM cohort.
• FDAVB is independently associated with diastolic dysfunction, indicated by an elevated E/e' ratio, in HCM patients.
• Further research is needed to elucidate the precise role and implications of FDAVB in hypertrophic cardiomyopathy.