P-Wave indices in the presence of atrial myxomas: a retrospective cohort analysis

BACKGROUND: Atrial myxoma is the most common primary cardiac neoplasm, which may cause embolisms, obstruction, and arrhythmias. Whether electrocardiographic P-wave indices carry diagnostic information for detecting atrial myxomas has not been systematically examined. METHODS: We retrospectively analyzed 83 patients: 39 with histologically confirmed atrial myxoma (34 left, 5 right atrial) and 44 age- and sex-matched controls. Seven P-wave indices were derived from 12-lead ECGs: duration, morphology in V1, voltage in lead I, axis, area in lead II, morphology-voltage-P-wave duration (MVP) score and dispersion. Logistic regression was used to identify possible predictors for atrial myxoma, with adjustment for age, sex, coronary artery disease, dyslipidemia, and smoking. RESULTS: Patients' median age was 60.0 [51.0-70.0] years; 77.1% were women. Atrial myxoma had a median size of 4.1 cm [IQR 2.5; 5.6]. Patients with a myxoma showed shorter P-wave duration (100 [80; 100] vs. 100 [100; 120] ms; p = 0.005) and lower lead-I voltage (0.07 [0.05; 0.08] vs. 0.09 [0.06; 0.10] mV; p < 0.001). On univariable analysis, both predicted tumor presence. Entered together, only voltage remained independently (OR 0.76 per 0.01 mV, 95% CI 0.63-0.91, p = 0.003) associated with atrial myxoma; duration became borderline due to collinearity (p = 0.078). After full adjustment, voltage remained robust (OR 0.70, 95% CI 0.55-0.89, p = 0.004). Within the tumor group, a larger maximal tumor diameter was associated with lower lead-I voltage (Spearman ρ = - 0.32; p = 0.044). CONCLUSIONS: ECG analysis of patients with atrial myxoma revealed reduced P-wave voltage in lead I, with relatively short P-wave duration. Reduced P-wave voltage in lead I was an independent predictor after full adjustment for cardiovascular comorbidities and may serve as a novel, easily available diagnostic adjunct for atrial mass lesions.