Differences in the prognostic value of the electrocardiographic pattern after cardiac resynchronization therapy according to age.

OBJECTIVES: In this cohort study, we analyzed if a specific pattern in three leads of the electrocardiogram (Rs in V1, Qr in aVL, or rS in I) was associated with outcomes after cardiac resynchronization therapy (CRT) depending on age. METHODS: Patients with CRT devices were included from January 2012 to April 2019. We divided the sample into 2 groups, those with age ≥ 75 years old and those younger. The primary endpoint was a composite of all-cause death and heart failure (HF) hospitalization at 1 year. RESULTS: We included 111 patients. Patients older than 75 years (26.1%, n = 29) had a significantly higher rate of hypertension and atrial fibrillation and received less frequently optimal medical therapy. The patterns were observed in 32 (39.0%) younger patients and 11 (37.9%) older patients. Patients who presented any of them had a lower incidence of the primary endpoint in the younger group (0 vs. 14%, p = 0.029), but not in the older group (9.1 vs. 27.8%, p = 0.24). The presence of a basal QRS duration greater than 160 ms was associated with a higher rate of the primary endpoint in the elderly (50 vs. 13%, p = 0.015), but not in the younger group (16.7 vs. 7.1%, p = 0.254). CONCLUSIONS: The presence of the selected patterns after CRT is associated with a lower incidence of all-cause death and hospitalization for HF in patients younger than 75 years, but not in those older than 75 years. Conversely, baseline QRS duration was associated with worse outcomes in older patients, but not in the younger group.

Differentiation of athlete's heart and hypertrophic cardiomyopathy by the fractal dimension of left ventricular trabeculae.

BACKGROUND: Differentiation between exercise induced adaptive myocardial hypertrophy (athlete's heart) and hypertrophic cardiomyopathy (HCM) is currently based on echocardiographic and cardiac magnetic resonance (CMR) criteria, but these may be insufficient in patients with subtle phenotype expression. This study aimed to assess whether left ventricular (LV) fractal pattern could permit to differentiate athlete's heart from HCM. METHODS: We recruited retrospectively 61 elite marathon runners, 67 patients with HCM, and 33 healthy subjects. A CMR study was performed in all subjects and the LV trabeculae fractal dimension (FD) was measured in end-diastolic frames of each short-axis cine sequence. For group comparison, the ratio of maximal myocardial wall thickness (mMWT)/indexed LV end-diastolic volume (LVED) was determined. RESULTS: As compared with athletes, patients with HCM had significantly (p < 0.001) greater FD in the LV basal (1.30 ± 0.07 vs. 1.23 ± 0.05) and apical (1.38 ± 0.06 vs. 1.30 ± 0.07) regions and in the whole heart (1.34 ± 0.05 vs. 1.27 ± 0.05). FD increased with age, left atrial area and indexed left ventricular mass (p < 0.05 for all) and correlated negatively with LV and RV end-diastolic volumes (p < 0.05 each). The addition of whole heart FD to the ratio of maximal myocardial wall thickness/indexed LVEDV lead to an improvement in the ability to discriminate HCM with a net reclassification index (NRI) of 71%. CONCLUSIONS: The FD regional distribution of the LV trabeculae differentiates patients with athlete's heart from patients with HCM. The addition of whole heart FD to the mMWT/indexed LVEDV ratio improves the predictive capacity of the model to differentiate both entities.