mechanical capture
Effective myocardial contraction and blood flow generation in response to electrical pacing stimuli, confirmed by palpable pulse or arterial pressure waveform.
Full Definition
Mechanical capture refers to the successful conversion of electrical pacing impulses into effective mechanical cardiac contraction that produces meaningful hemodynamic output. While electrical capture may show appropriate paced QRS complexes on ECG, mechanical capture requires confirmation through pulse palpation, arterial pressure monitoring, or echocardiographic visualization of ventricular contraction. In emergency pacing situations, achieving mechanical capture is essential for patient stability, and loss of mechanical capture despite electrical capture may indicate severe metabolic derangement, myocardial dysfunction, or pericardial tamponade.
Usage
Usage note: Always specify mechanical vs. electrical capture when documenting pacing effectiveness.
In Context
- "Transcutaneous pacing achieved electrical capture but mechanical capture remained inconsistent." — Emergency procedure note
- "Increase pacing output until reliable mechanical capture is achieved with palpable pulses." — Pacing protocol orders