[Echocardiographic features of small heart]

Area of Science:

• Cardiology
• Radiology
• Echocardiography

Background:

• A small cardiac silhouette on chest radiography (cardiothoracic ratio ≤ 40%) may have unclear clinical significance.
• Associated physical characteristics include straight spines and decreased chest anteroposterior diameters.
• Patients with small hearts often report cardiovascular complaints like chest pain, palpitations, dyspnea, and dizziness.

Purpose of the Study:

• To investigate the clinical significance of a small heart (cardiac silhouette) using echocardiography.
• To compare echocardiographic and hemodynamic parameters between individuals with small hearts and normal controls.

Main Methods:

• Echocardiographic study involving 60 individuals with small hearts (cardiothoracic ratio ≤ 40%) and 23 matched controls (cardiothoracic ratio 42%-50%).
• Two-dimensional and M-mode echocardiography were performed to assess cardiac dimensions and function.
• Hemodynamic indices at rest were calculated and compared between groups.

Main Results:

• The small heart group had significantly lower body weight and body surface area (BSA).
• Cardiac dimensions (left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left atrial dimension, left ventricular mass) were smaller in the small heart group but normalized when corrected for BSA.
• No significant differences in resting hemodynamic indices (heart rate, stroke volume, ejection fraction, cardiac output) were observed between the groups.
• Mitral valve prolapse (MVP) was diagnosed in 32% of the small heart group.

Conclusions:

• A small cardiac silhouette is associated with smaller body size and cardiac dimensions, but not with impaired cardiac function or hemodynamics when adjusted for body size.
• Mitral valve prolapse is a frequent finding in individuals with small hearts.
• Further investigation may be warranted for symptomatic individuals with small hearts, particularly those with MVP.