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Cardiodynamic and electrocardiographic alterations induced by blood sampling in normal and hypertensive donors
Insights
Blood sampling temporarily lowered blood pressure in hypertensive individuals, but worsened cardiodynamic function. Hypertensive donors experienced more persistent cardiac disturbances than normotensive individuals after blood donation.
Area of Science:
- Cardiology
- Hypertension Research
- Phlebotomy Effects
Background:
- Hypertension is a prevalent cardiovascular condition associated with altered cardiac function.
- Blood donation (phlebotomy) can transiently reduce blood pressure.
- The impact of phlebotomy on cardiodynamics in hypertensive individuals requires further investigation.
Purpose of the Study:
- To investigate the cardiodynamic responses to blood sampling in hypertensive versus normotensive individuals.
- To assess the effect of a 500 cc blood withdrawal on systolic time intervals in different blood pressure groups.
Main Methods:
- Recorded 12-lead electrocardiograms, phonocardiograms, piezocarotidograms, and Korotkov blood pressure.
- Measurements were taken before and after 500 cc blood sampling in 20 hypertensive and 20 normotensive donors.
- Analyzed cardiodynamic parameters, specifically systolic time intervals.
Main Results:
- Hypertensive donors exhibited more frequent and persistent cardiodynamic disturbances post-phlebotomy compared to normotensives.
- Blood sampling favorably reduced blood pressure values in both groups.
- An increased pre-ejection period/left ventricular ejection time ratio was the most significant alteration in hypertensives, indicating reduced ejection fraction.
Conclusions:
- Phlebotomy-induced blood pressure reduction offers less benefit to hypertensive individuals than the negative impact of blood loss on cardiac function.
- The hypoxic effect of blood loss appears to be more detrimental to cardiac performance in hypertensive individuals than the antihypertensive effect.
- Hypertensive individuals may experience more pronounced cardiac stress following blood donation.
Abstract:
The 12 routine electrocardiographic leads, apical phonocardiogram, piezocarotidogram, Korotkov blood pressure, sitting and standing, were recorded before and after 500 cc blood sampling in 20 hypertensive donors and 20 normals. The cardiodynamic (systolic time intervals) disturbances in hypertensive donors were more frequent and more persistent than those observed in the normotensive group, despite the favourable effect of the blood sampling on the blood pressure values. The most significant cardiodynamic alteration was the increase in the pre-ejection period/left ventricular ejection time--indicating a more reduced ejection fraction in the hypertensive group and pointing out that the improvement of left ventricular work by decreasing the blood pressure after blood sampling is less important than the hypoxic effect of blood loss.