AbstractExtrinsic compression of the left atrium (LA) due to oesophageal achalasia though uncommon has been reported in literature. This case report describes a middle‐aged man who presented with sudden onset dyspnoea and atrial fibrillation, but was later diagnosed to have achalasia cardia and megaoesophagus, resulting in extrinsic compression of the LA as well as posterobasal wall of the left ventricle (LV). The patient's early complaints of dysphagia and weight loss prompted a thorough study, with echocardiography helping to identify extrinsic compression of heart chambers caused by the dilated oesophagus. The left ventricular eccentricity index was increased secondary to compression by volume‐loaded megaoesophagus, which was one of the most notable findings. Through this case, we describe probably the first case of LV compression by achalasia cardia, in addition to LA and we want to highlight the fact that D‐shaped LV can also occur secondary to extrinsic etiologies particularly compression from posterior mediastinal structures.