myocardial oxygen supply-demand balance
The critical relationship between myocardial oxygen delivery and consumption that determines whether cardiac tissue receives adequate oxygenation.
Full Definition
The fundamental physiological principle governing cardiac tissue oxygenation, where myocardial oxygen supply must meet or exceed myocardial oxygen demand to prevent ischemia. Supply is determined by coronary blood flow, hemoglobin concentration, and arterial oxygen saturation, while demand is influenced by heart rate, contractility, preload, and afterload. In cardiac anesthesia, maintaining this balance is crucial during procedures such as coronary artery surgery, where disrupted coronary flow must be compensated by optimizing other supply factors and minimizing demand through careful anesthetic management.
Usage
Usage note: Always hyphenate the compound modifier 'supply-demand' when preceding the noun.
In Context
- "Maintaining optimal myocardial oxygen supply-demand balance required careful titration of heart rate and blood pressure." — Anesthesia plan
- "The patient's myocardial oxygen supply-demand balance was compromised by the combination of hypotension and tachycardia." — Clinical assessment