Left ventricular cavity obliteration: Mechanism of the intracavitary gradient and differentiation from hypertrophic obstructive cardiomyopathy

Mid-Ventricular Obliteration Diagnosed by Bedside-Focused Echocardiography in the Emergency Department in a Patient With Syncope and Associated Hypertrophic Cardiomyopathy: A Case Report

Syncope is a common complaint encountered in emergency medicine practice with multiple potential etiologies to investigate. The utility of focused bedside echocardiography allows emergency physicians to diagnose acute cardiovascular causes in a time-sensitive fashion. In this case report, a 61-year-old female with mixed aortic valve disease presented to the emergency department after a syncopal episode. In addition to standard electrocardiogram and laboratory testing, investigation with focused echocardiography performed at the point of care revealed mid-ventricular obliteration due to hypertrophic myocardial remodeling, left ventricular underfilling, and hyperdynamic performance. Key echocardiographic findings that may assist emergency physicians in recognizing and managing this physiological entity were discussed.

Evaluation of Left Ventricular Outflow Gradients During Staged Exercise Stress Echocardiography Helps Differentiate Pediatric Patients With Hypertrophic Cardiomyopathy From Athletes and Normal Subjects

BACKGROUND

Elevated left ventricular outflow tract (LVOT) gradients during exercise can occur in patients with hypertrophic cardiomyopathy (HCM) as well as in athletes and normal controls. The authors' staged exercise protocol calls for imaging at rest and during each stage of exercise to evaluate the mechanism of LVOT obstruction at each stage. They investigated whether this staged approach helps differentiate HCM from athletes and normal controls.

METHODS

They reviewed pediatric exercise stress echocardiograms completed between January 2009 and October 2017 at their center and identified those with gene-positive HCM, athlete's heart, and normal controls. Children with inducible obstruction (those with no LVOT gradient at rest who developed a LVOT peak gradient > 25 mm Hg during exercise) were included. LVOT peak gradient, velocity time integral, acceleration time, and deceleration time were measured at rest, submaximal stages, and peak exercise.

RESULTS

Compared with athletes, HCM patients had significantly higher LVOT peak gradients at rest (P = .019), stage 1 of exercise (P = .002), and peak exercise (P = .051), as well as a significantly higher change in LVOT peak gradient from rest to stage 1 (P = .016) and from rest to peak (P = .038). The acceleration time/deceleration time ratio of the LVOT Doppler was significantly lower in HCM patients compared with normal controls at peak exercise.

CONCLUSIONS

The HCM patients who develop elevated LVOT gradients at peak exercise typically manifest early obstruction in the submaximal stages of exercise, which helps to differentiate them from athletes and normal controls.