Does transient regional ischemia alter left ventricular diastolic function in open-chest dogs?
Transient regional myocardial ischemia causes a generalized alteration in left ventricular filling patterns in mid-diastole, affecting both ischemic and non-ischemic regions.
Simultaneous left ventricular echograms and high-gain pressure recordings were made during 30 s of regional myocardial ischemia induced by snare occlusions of the proximal left anterior descending (LAD) or left circumflex (LCx) coronary arteries in open-chest dogs. Left ventricular diastolic diameter (d) and pressure (p) were measured during slow filling. A normalized (for diameter D) distensibility estimate (DE = delta d/delta p/D) was calculated, as were slow filling slopes (SFSs) of the septum and posterior wall. After occlusion, significant (p less than 0.05) decreases of DE and anterior and posterior left-ventricular-wall mid-diastolic normalized slow-filling slopes (ASFS/D and PSFS/D) were observed. Correlations were noted between percentage decreases of DE and ASFS/D (r = 0.69, p less than 0.0001) and PSFS/D (r = 0.62, p less than 0.0001). No significant differences between decreases of DE and SFS were noted between ischemic and non-ischemic regions. Transient regional myocardial ischemia was associated with a generalized alteration in left ventricular filling patterns in mid-diastole.
Conetta et al. (Sun,) studied this question.