Repair of the circulation to heart muscle (myocardium) which is damaged by a blocked blood supply must be rapid for survival. Otherwise, the heart muscle can die. Abnormal heart rhythms can result from the sudden return of circulation and can lead to death. These rhythms are called reperfusion arrhythmias, including ventricular fibrillation (VF) (an extremely rapid, irregular rate) and ventricular tachycardia (VT) (rapid heart rate.)
Grape seed proanthocyanidin extract (GSPE) from red grape seeds is highly antioxidant. This study was done of the ability of GSPE to protect the heart. (GSPE protects the hearts of rabbits from reperfusion arrhythmias.) In the present study, rat heart circulation was blocked for 30 minutes and circulation was restored for 2 hours. The proteins produced by this damage to heart muscle were studied, comparing GSPE treated and non-GSPE treated hearts. The GSPE dose was 200 mg/kg/day for 4 weeks.
This study showed “GSPE can significantly reduce the incidence of reperfusion-induced VT and VF.” VF was reduced from 64% in untreated rats to 17% in GSPE-treated rats. VT was reduced from 91% in untreated rats to 33% in GSPE-treated rats. On microscopic study, only mild damage was seen in the GSPE-treated heart muscles.
Of 92 proteins studied, GSPE reduced levels of 3 of the proteins and increased 6 of the proteins. These proteins are probably related to protective effects of GSPE. GSPE was found to increase the amount of Na+/K+-ATPase (Na/K-pump.) The Na/K-pump prevents acidity inside of cells. Ischemia causes acidity on the inside of cells which can cause death to the cells.
CONCLUSION: Grape seed proanthocyanidin extract has been shown to protect heart muscle from reperfusion injury and from ventricular fibrillation and ventricular tachycardia. The increased Na/K-pump activity may be the method by which GSPE works to protect heart muscle. GSPE may be an effective antiarrhythmic drug.
NOTE: Read about grape resveratrol for cardioprotection.