The use of JWH-018, which is among the abused bonsai in the world and in our country due to its psychostimulant effect, is increasing day by day. Here, we evaluated the pharmacologic, cardiologic, biochemical, and histopathological effects of acute and subacute administration of low and high doses of JWH-018 in rats. The concentrations of JWH-018 and its metabolites in the heart were analyzed by liquid chromatography-mass spectrometry. JWH-018 administration caused many cardiac pathologies including dysregulation of the heart rate, and low blood pressure, also induced cardiac arrhythmia, branch blocks, and ischemic ECG changes depending on the drug dosage and the duration of treatment. Echocardiography did not show any significant structural or functional changes among the groups. The level of serum pro-brain natriuretic peptide which is an indication of impaired cardiac capabilities become observed to be elevated in a long-time excessive dose JWH-018 used group. Histopathologic findings consistent with acute myocardial ischemia were detected in the hearts of all groups. Loss of cross-talk of myocardial fibrils, and prominent eosinophilic contraction bands were early signs of acute myocardial infarction (4th and 12th hours), which were more common in subacute groups and associated with ischemia. Desmin staining was observed as increased in subacute groups and there were marked contraction band dyneins. There is growing pharmacological and pathological evidence of impairment, cardiac effects, and tissue injury attributable to this emerging class of drugs.