system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
In quiet breathing, and in the supine position, where is the apex beat of the hea located?
assistant
The correct answer is  The apex is the only point of the hea that can be directly identified on the precordium. A cardiac impulse may be visible at the apex, and palpation over it will confirm the presence of the apex beat. The apex is located in the left fifth intercostal space just medial to the midclavicular line. Ref: Ommen S.R., Nishimura R.A., Tajik A. (2011). Chapter 33. Hyperophic Cardiomyopathy. In V. Fuster, R.A. Walsh, R.A. Harrington (Eds), Hurst's The Hea, 13e.