Epi and endomyocardial pH allows the detection of acute right ventricular ischemia in pigs: a new evaluation method.
BACKGROUND
Techniques which identify acute right ventricular (RV) ischemia may help elucidate the pathophysiology of RV dysfunction. This study's goal was to validate an acute RV ischemia or infarction detection technique. Could RV endomyocardial and epimyocardial (interstitial) pH electrodes detect RV pH changes in an animal model of RV infarction produced by right coronary artery ligation?


METHODS
In ten adult anesthetized pigs, RV interstitial (pHepi) and transmural endomyocardial pH (pHendo) were measured before and serially after right coronary occlusion.


RESULTS
pHendo and pHepi fell significantly following coronary occlusion. The absolute and relative rates of change were greater for pHendo (mean pH decreased from 7.36 to 7.04) compared to pHepi ( mean pH of 7.28 vs 7.08; P <0.002). pH was unchanged in control experiments where the electrode was placed in the right atrial or ventricular chamber, and in sham-operated animals. These data suggest that coronary ligation induced RV ischemia produces RV myocardial pH changes, which can be recorded from an electrode placed against the RV wall via a central vein, or in the interstitium.


CONCLUSIONS
This newly described technique may be helpful in developing more discriminating tools to identify acute RV ischemia.
Skrobik
Yoanna K
YK
Critical Care Division, Maisonneuve Rosemont Hospital, Montréal, Québec, Canada. skrobiky@total.net
Filep
Janos G
JG
D000818:Animals; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000502:physiology; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006863:Hydrogen-Ion Concentration; D008026:Ligation; D008297:Male; D009203:Myocardial Infarction / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D009206:Myocardium / Q000737:chemistry*; D010496:Pericardium / Q000737:chemistry* / Q000503:physiopathology*; D013552:Swine; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology*