Critical Care Medicine-Neurologic Disorders>>>>>Heart Failure
Question 5#

A 64-year-old female with longstanding hypertension and mild aortic stenosis and subsequent left ventricular hypertrophy is in septic shock requiring vasopressors. You do a bedside echocardiogram, and left ventricular function is within normal limits. You decide to continue volume resuscitation, and she becomes more hypoxic requiring supplemental oxygen. You suspect heart failure with preserved ejection fraction (HFpEF).

Which of the following is NOT true regarding diastolic function?

A. Atrial fibrillation is tolerated poorly
B. End-stage renal disease is associated with diastolic dysfunction
C. Lusitropy is a determinant of the effectiveness of early diastole
D. Diastolic dysfunction can be a component of septic cardiomyopathy
E. Ventricular relaxation is only a passive process

Correct Answer is E

Comment:

Correct Answer: E

Heart failure with preserved ejection fraction is typically associated with hypertension, old age, coronary artery disease, diabetes mellitus, obstructive sleep apnea, and kidney disease. Left ventricular filling is dependent on myocardial relaxation (an active process requiring metabolic energy) and ventricular compliance (which is a passive process). Lusitropy is defined as the rate of myocardial relaxation, which is a cAMP-dependent pathway. Atrial fibrillation is not tolerated well because lack of atrial kick reduces ventricular filling, thereby limiting stroke volume. Septic cardiomyopathy causes both systolic and diastolic dysfunction.

References:

1. Little WC. Diastolic dysfunction beyond distensibility: adverse effects of ventricular dilatation. Circulation. 2005;112:2888.
2. Zakeri R, Chamberlain AM, Roger VL, Redfield MM. Temporal relationship and prognostic significance of atrial fibrillation in heart failure patients with preserved ejection fraction: a community-based study. Circulation. 2013;128:1085.