Effects of Malaria on Blood Pressure, Heart Rate, Electrocardiogram and Cardiovascular Response to Change in Posture
AbstractThe effect of malaria on blood pressure, heart rate, electrocardiogram and the cardiovascular responses to postural change were studied in malaria patients. Blood pressure was measured by the sphygmomanometric-auscultatory method. Standard ECG machine was used to record the electrocardiogram. Heart rate was obtained from the radial pulse or computed from the ECG.
Systolic blood pressure was lower in malaria patients compared with normal control subjects (106±3.4mmHg cf 120±2.0mmHg, p<0.05), Mean arterial pressure (MAP) was also lower (75±3.1 cf 91±1.7mmHg, p<0.05). Heart rates were higher in malaria patients (98±1.8 beats/min cf 66±2.1 beats/min, p<0.01). Change in posture from supine to standing resulted in immediate fall in blood pressure this was more pronounced in malaria patients. Heart rate showed little or no change in the control group but fell significantly, (from 98±1.0beats/min to 86±1.9beats/min, (p<0.05), in the first minute in malaria patients. Thereafter blood pressure and heart rate recovered completely within the 6min observation period. The ECG pattern showed little or no difference in control and malaria groups, however the amplitude of the QRS complex was lower in the malaria patients (2.2±0.2mV cf 2.9±0.3 mV, p<0.05). There was also a slight reduction in amplitude of the T waves (0.3±0.06mV cf 0.5±0.04mV, p<0.05). These results show that malaria may lower blood pressure, cause tachycardia and affect response to change in posture. Malaria may also reduce electrical activity of the heart.
Keywords: Blood pressure, Heart rate, ECG, Malaria, change in posture
Nig. Qt. J. Hosp. Med. Vol.12(1-4) 2002: 17-20