Adults with cyanotic congenital heart disease had higher basal left ventricular myocardial perfusion compared to healthy controls (0.77 vs. 0.55 ml/min/g, P<0.02), with similar hyperemic perfusion.
Case-Control (n=24)
Does myocardial perfusion reserve differ between adults with cyanotic congenital heart disease and healthy controls?
Adults with cyanotic congenital heart disease appear to undergo coronary circulation remodeling that preserves hyperemic myocardial perfusion despite chronic hypoxemia and erythrocytosis.
Absolute Event Rate: 0.77% vs 0.55%
p-value: p=<0.02
In patients with cyanotic congenital heart disease (CCHD), a right-to-left shunt results in systemic hypoxemia. Systemic hypoxemia incites a compensatory erythrocytosis, which increases whole blood viscosity. We considered that these changes might adversely influence myocardial perfusion in CCHD patients. Basal and hyperemic (intravenous dipyridamole) perfusion measurements were obtained with 13Nammonia positron emission tomographic imaging in left (LV) and right (RV) ventricular and septal myocardium in 14 adults with CCHD age: 34.1 yr (SD 6.5); hematocrit: 62.2% (SD 4.8)] and 10 healthy controls age: 34.1 yr (SD 6.5). In patients, basal perfusion measurements were higher in LV 0.77 (SD 0.24) vs. 0.55 ml x min(-1) x g(-1) (SD 0.09), P < 0.02, septum 0.71 (SD 0.16) vs. 0.49 ml x min(-1) x g(-1) (SD 0.09), P < 0.001, and RV 0.77 (SD 0.30) vs. 0.38 ml x min(-1) x g(-1) (SD 0.09), P < 0.001. However, basal measurements normalized for the rate-pressure product were similar to those of controls. Calculated oxygen delivery relative to rate-pressure product was higher in the patients 2.2 (SD 0.8) vs. 1.6 (SD 0.4) x 10(-5) ml O2 x min(-1) x g tissue(-1) x (beats x mmHg)(-1) in the LV, P < 0.05, and 2.0 (SD 0.7) vs. 1.4 (SD 0.3) x 10(-5) ml O2 x min(-1) x g tissue(-1) x (beats x mmHg)(-1) in the septum, P < 0.01. Hyperemic perfusion measurements in CCHD patients did not differ from controls LV, 1.67 (SD 0.60) vs. 1.95 ml x min(-1) x g(-1) (SD 0.46); septum, 1.44 (SD 0.56) vs. 1.98 ml x min(-1) x g(-1) (SD 0.69); RV, 1.56 (SD 0.56) vs. 1.65 ml x min(-1) x g(-1) (SD 0.64), P = not significant, and coronary vascular resistances were comparable LV, 55 (SD 25) vs. 48 mmHg x ml(-1) x g x min (SD 16); septum, 67 (SD 35) vs. 50 mmHg x ml(-1) x g x min (SD 21); RV, 59 (SD 26) vs. 61 mmHg x ml(-1) x g x min (SD 27), P = not significant. These findings suggest that adult CCHD patients have remodeling of the coronary circulation to compensate for the rheologic changes attending chronic hypoxemia.
Brunken et al. (Sat,) conducted a case-control in Cyanotic congenital heart disease (n=24). Cyanotic congenital heart disease vs. Healthy controls was evaluated on Basal myocardial perfusion in the left ventricle (ml/min/g) (p=<0.02). Adults with cyanotic congenital heart disease had higher basal left ventricular myocardial perfusion compared to healthy controls (0.77 vs. 0.55 ml/min/g, P<0.02), with similar hyperemic perfusion.