Case Presentation: A thirty-seven year old female with past medical history of hypertension presented with syncope and chest pain. The pain was non-exertional, substernal, pressure like, associated with lightheadedness, dizziness and shortness of breath occurring intermittently for past few days. Her father died from myocardial infarction at age forty-two and she smoked one pack per day for many years. Neurological and cardiovascular examinations was unremarkable. Workup for ischemia and syncope including EKG, serial troponins and nuclear stress test were negative. Echocardiogram revealed a normal ejection fraction and no structural heart disease. Due to unclear etiology of syncope she was sent home with event monitor to follow up outpatient with cardiology. During the next two weeks she continued to have recurrent episodes of similar chest pains. She presented to her cardiologist with bradycardia and dizziness and was taken to the emergency department immediately. Troponins again were negative and EKG did not show any new changes. Review of the event monitor however revealed intermittent complete heart block. Overnight patient continued to have episodes of substernal chest pain, shortness of breath and dizziness. A significant finding was inferior lead 1mm ST elevations and third degree heart block with junctional escape concurrently with the chest pains. Although this pointed more towards vasospastic angina, atherosclerotic coronary artery disease had to be ruled out, therefore patient was started on heparin and nitroglycerin infusions. Subsequently, patient underwent left heart catheterization that showed evidence of right coronary artery vasospasm and diffuse small vessel coronary artery disease but no isolated lesion to require intervention thereby confirming the diagnosis of vasospastic angina. The patient underwent a dual chamber permanent pacemaker placement on the same day. She was discharged on isosorbide dinitrate and continues to follow up outpatient without recurrence of chest pain or EKG abnormalities. 

Discussion: Vasospastic angina is a unique syndrome with intermittent coronary vasospasm producing chest pain and ST-segment elevation mimicking acute coronary syndrome. Although a number of rhythm disturbances can occur due to this, complete heart block (CHB) has been rarely documented. As this case demonstrates, among the list of known arrhythmias caused by vasospastic angina, CHB also needs to be considered. It is believed that focal or diffuse smooth muscle hyper-reactivity causing vasospasm induces ischemia and myocardial dysfunction that can manifest as conduction or wall motion abnormalities. Distinguishing this from ST elevation myocardial infarction can be challenging at times but the transient nature, rapid reversal of ST-segment changes, responsiveness to calcium channel blockers and nitroglycerin proves to be helpful.

Conclusions: Transient episodes of atypical chest pain associated with syncope or pre-syncopal symptoms in a relatively young and healthy female should raise suspicion for vasospastic etiology for arrhythmias. This case illustrates a unique presentation of vasospastic angina presenting as complete heart block.