Abstract
The present study was designed to determine whether conversion to the beating, nonworking (BNW) heart would diminish fibrillation-induced regional ischemia distal to a critical coronary stenosis. Ten mongrel dogs were placed on total cardiopulmonary bypass with a critical stenosis applied to the left anterior descending coronary artery (LAD). The time on total bypass was divided into three equal 50-minute periods during which the hearts were maintained alternately in sinus rhythm or ventricular fibrillation. When BNW hearts were fibrillated, intramyocardial carbon dioxide tension (PmCO2 ) in the LAD supplied subendocardium rose from 73 ± 7 (±SEM) to 120 ± 14 mm Hg (p < 0.001), and intramyocardial oxygen tension (PmO2 ) fell from 24 ± 4 to 10 ± 2 mm Hg (p < 0.005). Regional arterial-coronary venous lactate difference (A-CV lac) fell from 13.8 ± 3.8 mg% (extraction) to -10.8 ± 3.2 mg% (production) (p < 0.005). When fibrillating hearts were converted to the BNW state, PmO2 rose from 12 ± 2 to 19 ± 4 mm Hg and PmCO2 decreased from 101 ± 9 to 85 ± 4 mm Hg. A-CV lac rose from -6.5 ± 2.6 mg% (production) to 10.4 ± 4.8 mg% (extraction) (p < 0.01). These results suggest that in a region of myocardium distal to a critical stenosis, ventricular fibrillation during bypass results in regional myocardial ischemia whereas the BNW state does not. This ischemia likely is due to the inability of flow in the stenosed coronary artery to increase in response to the increased oxygen demand of fibrillation. Furthermore, conversion to the BNW state can reverse the ischemia which develops in the fibrillating state.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 57-66 |
| Number of pages | 10 |
| Journal | Surgery |
| Volume | 83 |
| Issue number | 1 |
| State | Published - 1978 |
| Externally published | Yes |
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Development of regional myocardial ischemia distal to a critical coronary stenosis during cardiopulmonary bypass : Comparison of the fibrillating vs. the beating nonworking states. / Schaff, Hartzell V; Ciardullo, Robert C.; Flaherty, John T.; Gott, Vincent L.
In: Surgery, Vol. 83, No. 1, 1978, p. 57-66.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Development of regional myocardial ischemia distal to a critical coronary stenosis during cardiopulmonary bypass
T2 - Comparison of the fibrillating vs. the beating nonworking states
AU - Schaff, Hartzell V
AU - Ciardullo, Robert C.
AU - Flaherty, John T.
AU - Gott, Vincent L.
PY - 1978
Y1 - 1978
N2 - The present study was designed to determine whether conversion to the beating, nonworking (BNW) heart would diminish fibrillation-induced regional ischemia distal to a critical coronary stenosis. Ten mongrel dogs were placed on total cardiopulmonary bypass with a critical stenosis applied to the left anterior descending coronary artery (LAD). The time on total bypass was divided into three equal 50-minute periods during which the hearts were maintained alternately in sinus rhythm or ventricular fibrillation. When BNW hearts were fibrillated, intramyocardial carbon dioxide tension (PmCO2 ) in the LAD supplied subendocardium rose from 73 ± 7 (±SEM) to 120 ± 14 mm Hg (p < 0.001), and intramyocardial oxygen tension (PmO2 ) fell from 24 ± 4 to 10 ± 2 mm Hg (p < 0.005). Regional arterial-coronary venous lactate difference (A-CV lac) fell from 13.8 ± 3.8 mg% (extraction) to -10.8 ± 3.2 mg% (production) (p < 0.005). When fibrillating hearts were converted to the BNW state, PmO2 rose from 12 ± 2 to 19 ± 4 mm Hg and PmCO2 decreased from 101 ± 9 to 85 ± 4 mm Hg. A-CV lac rose from -6.5 ± 2.6 mg% (production) to 10.4 ± 4.8 mg% (extraction) (p < 0.01). These results suggest that in a region of myocardium distal to a critical stenosis, ventricular fibrillation during bypass results in regional myocardial ischemia whereas the BNW state does not. This ischemia likely is due to the inability of flow in the stenosed coronary artery to increase in response to the increased oxygen demand of fibrillation. Furthermore, conversion to the BNW state can reverse the ischemia which develops in the fibrillating state.
AB - The present study was designed to determine whether conversion to the beating, nonworking (BNW) heart would diminish fibrillation-induced regional ischemia distal to a critical coronary stenosis. Ten mongrel dogs were placed on total cardiopulmonary bypass with a critical stenosis applied to the left anterior descending coronary artery (LAD). The time on total bypass was divided into three equal 50-minute periods during which the hearts were maintained alternately in sinus rhythm or ventricular fibrillation. When BNW hearts were fibrillated, intramyocardial carbon dioxide tension (PmCO2 ) in the LAD supplied subendocardium rose from 73 ± 7 (±SEM) to 120 ± 14 mm Hg (p < 0.001), and intramyocardial oxygen tension (PmO2 ) fell from 24 ± 4 to 10 ± 2 mm Hg (p < 0.005). Regional arterial-coronary venous lactate difference (A-CV lac) fell from 13.8 ± 3.8 mg% (extraction) to -10.8 ± 3.2 mg% (production) (p < 0.005). When fibrillating hearts were converted to the BNW state, PmO2 rose from 12 ± 2 to 19 ± 4 mm Hg and PmCO2 decreased from 101 ± 9 to 85 ± 4 mm Hg. A-CV lac rose from -6.5 ± 2.6 mg% (production) to 10.4 ± 4.8 mg% (extraction) (p < 0.01). These results suggest that in a region of myocardium distal to a critical stenosis, ventricular fibrillation during bypass results in regional myocardial ischemia whereas the BNW state does not. This ischemia likely is due to the inability of flow in the stenosed coronary artery to increase in response to the increased oxygen demand of fibrillation. Furthermore, conversion to the BNW state can reverse the ischemia which develops in the fibrillating state.
UR - http://www.scopus.com/inward/record.url?scp=0017911993&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0017911993&partnerID=8YFLogxK
M3 - Article
C2 - 619472
AN - SCOPUS:0017911993
VL - 83
SP - 57
EP - 66
JO - Surgery (United States)
JF - Surgery (United States)
SN - 0039-6060
IS - 1
ER -