52 yo M with dizziness and palpitations

Original case by Brandon Fainstad, MD.
Edits and graphics by Yilin Zhang, MD.



52 year old man presents with one week of episodic dizziness, palpitations and shortness of breath that last for 30 seconds and have occurred both at rest and with exertion. He has also noticed increased muscle aches and fatigue following his usual work outs, along with an intentional 10lb weight loss. On ROS he denies fevers, chills, nausea/vomiting, chest pain, orthopnea/PND, cough or skin changes. He has a history of an inherited non-ischemic cardiomyopathy with an LVEF of 35%, a primary prevention AICD in place that has never fired, paroxysmal atrial fibrillation and obstructive sleep apnea. He takes amiodarone (started 4 mos ago for control of symptomatic AF), carvedilol, digoxin, eplerenone, fenofibrate, furosemide, losartan, simvastatin and warfarin.  He does not smoke tobacco, drink alcohol or use illicit drugs.

What are some potential explanations for this patient’s symptoms?


On exam, he is afebrile, HR 82bpm, BP 120/85 and sating 96% on room air.  He appears comfortable, no overt thyromegaly or palpable nodules, and clear lung sounds to auscultation. Cardiac exam is notable for regular rhythm without murmurs, non-elevated JVP and no dependent edema.  Abdomen is soft and non-tender.

BMP, LFTs, CBC, BNP and trop nml
INR >10 (Of note, his INR had previously been consistently 2-3, and he denies dose or diet changes)

Normal sinus rhythm


Is the AICD lead in the appropriate location? How can you tell this is an AICD and not a single lead pacemaker?

Which additional tests you want to obtain to evaluate his palpitations. 

How do you interpret these findings? What is a potential explanation for this patient’s elevated INR? 

What do you want to do about his elevated INR? 




  1. Batcher, Elizabeth L., X. Charlene Tang, Bramah N. Singh, Steven N. Singh, Domenic J. Reda, and Jerome M. Hershman. “Thyroid Function Abnormalities during Amiodarone Therapy for Persistent Atrial Fibrillation.” The American Journal of Medicine 120.10 (2007): 880-85.
  2. “Guidelines for Reversal of Anticoagulants.” University of Washington Pharmacy Department, Feb. 2016, depts.washington.edu/anticoag/home/content/guidelines-reversal-anticoagulants.

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