From the Guidelines
ECG findings in Hypertrophic Obstructive Cardiomyopathy (HOCM) are abnormal in 75% to 95% of patients, including left ventricular hypertrophy, repolarization changes, and other abnormalities such as Wolff-Parkinson-White pattern, which may suggest certain phenocopies of HCM 1.
Key ECG Findings
- Left ventricular hypertrophy with increased QRS voltage, particularly in the precordial leads
- ST segment depression and T wave inversions, especially in the lateral leads (I, aVL, V5-V6)
- Left atrial enlargement, manifested as a prolonged, notched P wave in lead II (P mitrale)
- Pathological Q waves in the inferior and lateral leads, mimicking prior myocardial infarction
- Left axis deviation
- Pre-excitation patterns or conduction abnormalities
- Rhythm disturbances such as atrial fibrillation, ventricular ectopy, or non-sustained ventricular tachycardia
Importance of ECG Monitoring
- Ambulatory electrocardiographic monitoring is necessary for patients with HCM to identify those at risk for sudden cardiac death (SCD) and to guide management of arrhythmias 1.
- Extended monitoring is most useful for determining the cause of symptoms or diagnosing atrial fibrillation (AF)
- Predictors of AF include left atrial dilatation, advanced age, and NYHA class III to class IV HF, and patients with these characteristics should be assessed more frequently and possibly including extended ambulatory electrocardiographic screening 1
Clinical Implications
- A normal ECG does not exclude the diagnosis of HOCM, and echocardiography remains the gold standard for confirmation
- ECG findings result from the underlying pathophysiology of asymmetric septal hypertrophy and myocardial fiber disarray characteristic of HOCM
- The 12-lead ECG is also useful in identifying other abnormalities, such as Wolff-Parkinson-White pattern, which may suggest AF, and should be performed as part of the initial evaluation and periodic follow-up (every 1 to 2 years) 1.
From the Research
ECG Findings in HOCM
- The provided studies do not specifically mention ECG findings in Hypertrophic Obstructive Cardiomyopathy (HOCM) 2, 3, 4, 5, 6.
- However, it is known that ECG changes can occur in HOCM, but the studies provided focus on the diagnosis, treatment, and management of the condition rather than ECG findings.
- One study mentions that after septal myectomy, partial or complete left bundle branch block is a frequent finding on the postoperative ECG 5.
- The studies emphasize the importance of proper diagnosis and management of HOCM, including the use of various diagnostic modalities and treatment options 2, 3, 4, 5, 6.
Diagnostic Criteria and Instrumental Methods
- The studies discuss the diagnostic criteria and instrumental methods for HOCM, including echocardiography, cardiac imaging, and genetic testing 2, 3, 4, 5, 6.
- However, they do not specifically address ECG findings as a diagnostic criterion for HOCM.