Abstract
Background
Cardiac disease remains an important cause of maternal morbidity and mortality globally. Peripartum cardiomyopathy (PPCM), defined as heart failure secondary to left ventricular (LV) systolic dysfunction in previously healthy women towards the end of pregnancy or up to five months following delivery, can result in cardiogenic shock due to severe LV dysfunction or arrhythmias leading to sudden cardiac death. Cardiac electrical activity and its relationship to cardiac dysfunction have not yet been interrogated in large multi-centre studies.
Purpose
This study aimed to identify the ECG abnormalities associated with PPCM; their relationship with echocardiographic structural and functional abnormalities and explore regional and ethnic differences in ECG features.
Methods
We included the first 411 patients enrolled into the EURObservational PPCM registry (EORP). Baseline demographic, clinical and echocardiographic data were collected. ECGs were analysed for rate; rhythm; QRS width, axis and morphology; and QTc interval.
Results
Mean age of the women (from >40 countries) was 30.7±6.4 years. More than two thirds of patients presented with NYHA class III or IV (with no regional differences). The median QRS rate was 102bpm (IQR 87–117). More than half presented with sinus tachycardia (QRS rate >100bpm), whereas atrial fibrillation was rare (2.27%). The mean QRS width was 90.1ms ±21.5, with regional differences (ESC 93.8ms ±21.7 vs. non-ESC 86.8ms ±20.8, P<0.001). Left bundle branch block (LBBB) was reported in 9.30% with no regional or ethnic differences. Left ventricular hypertrophy (LVH) was present in a quarter of the cohort, and more prevalent amongst African (59.62%) and Asian (23.17%) than Caucasians (7.63%, P<0.001). The median QTc by Bazett was 456.7ms (IQR 409–490.7) and almost half (47.11%) had prolonged QTc (>460ms). The median LVEDD was 60mm (IQR 55–65) on echocardiography. Compared with their Asian and Caucasian counterparts, African patients were more likely to have LV dilatation (LVEDD>53mm: 70.11%, 79.31% and 89.42% respectively; P=0.004). The median LV ejection fraction (LVEF) was 32.50% (IQR 25–39) with no significant regional or ethnic differences. Sinus tachycardia predicted poor systolic function (OR 1.85 [95% CI 1.20–2.85], p=0.006). LVEF <35% was associated with a significantly higher QRS rate (median rate 107 vs. 98bpm, p=0.002). Women with LVEDD ≥53mm had a longer mean QRS duration (92.0±22.4 vs. 82.4±15.4ms, p<0.001) and frequency of LBBB (11.15% vs 1.54%, p=0.016). LBBB was a predictor of LVEDD >53mm (sensitivity 11.15%; specificity 98.46%; PPV 97.14%; NPV 19.10%; OR 8.02 [95% CI 1.08–59.66], p=0.042).
Conclusion
Patients with PPCM commonly present with sinus tachycardia, LVH, and/or prolonged QTc interval on their ECG. Wide QRS and/or LBBB, were associated with LVEDD>53mm. Sinus tachycardia, however, was associated with LVEF<35%. Risk of arrhythmia in those with prolonged QTc remains to be ascertained.
Acknowledgement/Funding
Heart Failure Association of the ESC
Peripartum cardiomyopathy
