Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

BACKGROUND: The interrelations between myocardial stroke work and coronary flow velocity have not been fully defined during aortic valve replacement or with different cardioplegias. METHODS: Twenty-six patients (15 men age 63+/-13 years) who had elective isolated aortic valve replacement were studied by transesophageal Doppler echocardiography with simultaneous high fidelity left ventricular pressure. Fifteen patients received cold blood cardioplegia and 11 had warm blood cardioplegia. Myocardial stroke work and flow velocities in proximal left anterior descending coronary artery were quantified simultaneously before cardiopulmonary bypass and at 1, 6, 12, and 20 hours afterwards. RESULTS: Myocardial stroke work decreased postoperatively in both groups (160+/-19 versus 228+/-19 mJ/cm3 per minute, with cold blood cardioplegia; 135+/-22 versus 227+/-22 mJ/cm3 per minute with warm blood cardioplegia; both p<0.001 versus time, but p>0.05 versus cardioplegia, by two-way analysis of variance). Left anterior descending artery flow velocity-time integral per minute increased significantly in both groups (26.1+/-2.1 versus 15.0+/-2.1 m/min with cold blood cardioplegia; 32.8+/-2.5 versus 14.4+/-2.5 m/min with warm blood cardioplegia; both p<0.001 versus time, but p>0.05 versus cardioplegia). Thus, at 1 hour postoperatively the mJ x cm(-3) x m(-1) x min ratio of myocardial stroke work to left anterior descending artery flow velocity-time integral decreased significantly in both groups (4.3+/-1.6 versus 16.3+/-1.7 mJ x cm(-3) x m(-1) x min with warm blood cardioplegia, and 7.4+/-1.4 versus 17.9+/-1.4 J x cm(-3) x m(-1) x min with cold blood cardioplegia; both p<0.001 versus time). Warm blood cardioplegia was also associated with a lower mean ratio perioperatively than that with cold blood cardioplegia (7.8+/-0.9 versus 10.9+/-0.7 mJ x cm(-3) x m(-1) x min, p = 0.014). CONCLUSIONS: Coronary hyperemia occurs for at least 20 hours postoperatively when myocardial stoke work has decreased. The ratio of myocardial stroke work to coronary flow velocity appears to be more sensitive than either alone in differentiating the effect of warm versus cold blood cardioplegia.

Type

Journal article

Journal

Ann Thorac Surg

Publication Date

03/1999

Volume

67

Pages

705 - 710

Keywords

Aortic Valve, Aortic Valve Stenosis, Blood Flow Velocity, Blood Pressure, Cardiac Output, Cardiopulmonary Bypass, Coronary Circulation, Echocardiography, Transesophageal, Electrocardiography, Female, Heart Arrest, Induced, Heart Rate, Heart Valve Prosthesis Implantation, Humans, Male, Middle Aged, Myocardial Contraction, Stroke Volume, Temperature, Ventricular Function, Left, Ventricular Pressure