Standardization of the apex beat in the full left lateral position and its diagnostic value in detecting left...

The aims of this study were to determine the characteristics of the apex beat in the full left lateral position in healthy adults, and to assess its value in the diagnosis of left ventricular dilatation.

77 healthy adults and 27 patients with left ventricular dilatation were evaluated by history, physical examination, electrocardiography, apexcardiography and complete transthoracic echocardiographic examination. The location, size and quality of the apex beat were determined in the 90-degree left lateral position. A palpable apex beat, located in the 5th or 6th intercostal space, was recorded in 87% of the healthy adults. The lateral margin was palpated in a 3-cm-wide area from the left anterior axillary line (LAAL) towards the mid-clavicular line (MCL). The mean diameter and area were 2.5 +/- 0.5 cm and 5.0 +/- 2.5 cm2, respectively. In 51% the apex impulse intensity was of medium degree, in 25% weak and in 24% strong. It was palpable in all patients with left ventricular enlargement in the 5th, 6th or 7th intercostal space. The lateral margin was located in a 4.5-cm-wide area, 3.5 cm left from the LAAL to 1 cm right from it. The mean diameter and area were 5.0 +/- 1.0 cm and 20.0 +/- 7.0 cm2, repectively. The intensity was weak in 56% and medium degree in the rest. The diameter > or = 4.0 cm was sensitive (96%) and specific (96%) for the enlarged left ventricle. The location of the apex beat with the cut-off point in the LAAL was equally sensitive but less specific (63%) for left ventricular dilatation.

Palpation of the apex beat in the full left lateral position is very suitable for detecting the left ventricular dilatation at bedside. The size of the apex beat appears to be a more reliable diagnostic sign of left ventricular dilatation than its location.