Life-threatening hypokalemia associated with profound electrocardiographic manifestations in thyrotoxic periodic paralysis

We describe a case of thyrotoxic periodic paralysis (TPP) associated with profound electrocardiographic abnormalities and cardiac arrhythmias along with a brief literature review. A 38-year old Hispanic male presented with a history of intermittent profound lower extremity weakness which went undiagnosed for over a year before a diagnosis of thyrotoxic periodic paralysis (TPP) was made. The patient experienced ventricular tachycardia, as well as complete atrioventricular block and a right bundle branch block requiring urgent treatment. Although all these electrocardiographic abnormalities are known to occur in TPP, they are rarely manifest together in a single patient. TPP is a frequently unrecognized but life-threatening disorder which requires a high index of suspicion for prompt diagnosis and treatment. Our patient demonstrates the multiple electrocardiographic abnormalities associated with TPP and severe hypokalemia. Unfortunately, this condition went unrecognized for over a year, highlighting the need for better recognition of this potentially fatal disorder.