Abstract:
Khat is a flowering plant whose leaves and stems are chewed for excitement purposes. It is
very common in east African and Arabian countries. Khat can cause mood changes, increased
alertness, hyperactivity, anxiety, elevated blood pressure, and heart diseases. However, the
effect of khat on the heart has not been studied exclusively. The purpose of this study was to
investigate the effect of khat chewing and rehabilitation therapy for khat addiction on heart
activity.
ECG signals were recorded from 50 subjects (25 chewers and 25 controls) before and after
chewing session to investigate the effect of khat on heart activity. In addition, ECG signals
from 5 subjects were recorded in the first and eighth day of rehabilitation therapy for
investigating the effect of rehabilitation therapy for khat addiction. All the collected signals
were annotated, denoised, features extracted and analysed.
After chewing khat, the average heart rate of the chewers was increased by 4.82%, with 3
subjects out of 25 were prone to tachycardia. 1.39% QRS duration and 20.07% R-peak
amplitude reduction were observed after chewing session. Moreover, heart rate variability was
reduced by 18.24% indicating the effect of khat on suppressing sympathetic and
parasympathetic nerve actions. After rehabilitation therapy, the average heart rate was reduced
by 11.66%, while heart rate variability (HRV), QRS duration, and RR interval were increased
by 25.43%, 3.49%, and 12.53%, respectively.
The findings demonstrate that, khat chewing raises heart rate, lowers heart rate variability, or
puts the heart under stress by lowering R-peak amplitude and QRS duration, which in turn
increases the risk of premature ventricular contraction, arrhythmia, and heart failure. The
results also show that rehabilitation therapy from khat addiction has a major impact on restoring
cardiac activity to normal levels.
