Myocardial Degradation and Left Bundle Branch Block Predict Conversion to Low Ejection Fraction in Heart Failure With Preserved Systolic Function

Abstract

The authors prospectively investigated whether left bundle branch block (LBBB) and myocardial degradation as indicated by elevated troponin T (tnT) predict the phenomenon of systolic conversion to low ejection fraction (EF <or=40%) in patients with nonsignificant coronary disease and heart failure with preserved systolic function (HFPSF) (initial EF >40%). Thirty consecutive patients with HFPSF were included and followed over a 4-year interval. A follow-up EF assessment was performed in 25 patients. Six of 15 patients with tnT >or=0.01 ng/mL demonstrated systolic conversion to low EF on follow-up, while none of the 10 patients with tnT <0.01 ng/mL experienced this phenomenon (P=.03). Five of the 6 converters presented with LBBB, while only 1 of the 19 nonconverters had this abnormality (P=.0007). Four of the 6 converters had an initial EF >50%. Myocardial degradation and LBBB predicted systolic conversion in HFPSF patients with nonsignificant coronary disease.

Predictors of Left Ventricular Function Deterioration in Patients With Left Bundle Branch Block and Ejection Fraction >50%

“…EF deterioration to values ≤40% was associated in our cohort with history of CHF diagnosed prior to the baseline echocardiogram. Several studies have demonstrated a link between interventricular dyssynchrony and LV function dysfunction . In a study investigating patients with CHF and baseline normal systolic function, we were able to demonstrate a significant LVEF drop in the subgroup with LBBB in contrast to the patients without this conduction anomaly .…”

“…Several studies have demonstrated a link between interventricular dyssynchrony and LV function dysfunction. 2,9 In a study investigating patients with CHF and baseline normal systolic function, we were able to demonstrate a significant LVEF drop in the subgroup with LBBB in contrast to the patients without this conduction anomaly. 2 Interestingly, in the current study, admissions for CHF with preserved EF as well as cardiac admissions were more frequent in patients prone to EF deterioration, stressing the importance of this phenomenon.…”

“…The study suggests a triage strategy for patients with LBBB and baseline EF >50% predisposed to develop LV dysfunction. Our investigation is part of a small body of hypothesis‐generating literature that may advocate the need of prophylactic resynchronization therapy in select patients with LBBB and normal or near‐normal EF. While the Pacing to Avoid Cardiac Enlargement (PACE) trial demonstrated that an artificially induced LBBB can effectively induce a drop in EF, a study investigating patients with dilated cardiomyopathy and EF 19%±6% showed 19% of these patients recovering to EF >50% after 1 year of resynchronization therapy .…”

“…In the presence of congestive heart failure (CHF) symptoms and an ejection fraction (EF) ≥40%, more than 75% of patients featuring LBBB experienced EF deterioration to values ≤40% . In the present study we examined the natural history of LV function in a population with LBBB and baseline EF >50%, and assessed the role of several variables in predicting the phenomenon of EF deterioration to values ≤40%.…”

Clinical Determinants of Left Ventricular Ejection Fraction Deterioration in Patients Suffered From Complete Left Bundle Branch Block

“…New-onset LBBB leading to poor prognosis (even in asymptomatic patients) rises several questions concerning the importance of assessing relationship between this arrhythmic phenomenon and other functional and structural cardiac deterioration such as cardiac ischemic events ( 1 ), left ventricular hypertrophy ( 2 ), heart failure state ( 3 ), and left ventricular dysfunction ( 4 ). In this regard, the deleterious impact of LBBB on left ventricular systolic and diastolic function has been established even in patients without overt underlying heart disease ( 5 ).…”