AimTo assess whether the number of patients with a cardiac chief complaint and their characteristics differed between before and after two major earthquakes that struck Croatia in 2020.MethodsWe collected data on all visits of patients with a cardiac chief complaint examined in the emergency departments of six hospitals nearest to the epicenters. Patients seen during the 7 days before the earthquake were compared with those seen on the day and during the 6 days after the earthquake.ResultsPatients seen after the earthquake were younger (68 [59-79] vs 72.5 [65-80];P< 0.001) and less frequently had cardiovascular disease (32.9% vs 42.8%;P< 0.001). This group less frequently had the primary diagnosis of acute myocardial infarction (AMI) (15.6% vs 21.9%;P= 0.005), heart failure (9.3% vs 19.4%;P< 0.001), dysregulated hypertension (13.9% vs 19.4%;P= 0.01), but more frequently had non-anginal chest discomfort (28.8% vs 18.0%;P< 0.001). In a subgroup analysis of patients seen in hospitals located within 20 km from the epicenter, significantly more patients seen after the earthquake compared with those seen before the earthquake presented with AMI (14.5% vs 22.8%;P= 0.028), acute elevation of blood pressure (10% vs 21.8%,P= 0.001), and paroxysmal arrhythmias treated with electrocardioversion (0.9% vs 4.5%,P= 0.022).ConclusionAfter two moderately strong earthquakes, hospitals within 20 km from the epicenter saw a significant increase in acute cardiac conditions such as elevated blood pressure, AMI, and cardioverted arrhythmias. Eventually, these earthquakes had no impact on the outcomes of the studied population.