Arrhythmia Masquerading as Cardiac Ischemia

A 45-year-old woman with a history of medication-controlled essential hypertension, stage 2 chronic kidney disease, type 2 diabetes mellitus, and a pack-a-day cigarette habit presented less than 60 minutes after acute onset of severe shortness of breath that awoke her from sleep. She had felt well the previous day, and went to bed with no complaints.   Around 4 a.m., she woke up from sleep very dyspneic, with moderate chest “discomfort” over her left chest that radiated to her back and was unchanged by position or respirations. She denied other symptoms such as fever, cough, nausea, vomiting, numbness, or abdominal pain.   Her blood pressure was 138/76 mm Hg, pulse 87 bpm, respiratory rate 26, and SpO2 was 95%. She was afebrile, and her physical exam was unremarkable: clear breath sounds, no S3 or murmur, and no lower extremity edema. She felt slightly less dyspneic with supplemental oxygen. She was treated with an aspirin orally. A sublingual nitroglycerin improved her chest discomfort, and a chest radiograph was clear. Her presenting electrocardiogram is shown in Figure 1.   The ECG is consistent with a supraventricular tachycardia (SVT), likely to be atypical atrioventricular nodal reentrant tachycardia (AVNRT). The key feature to note is the absence of P waves before the QRS complex and retrograde P-waves evident following the QRS as part of the T-wave. The discomfort in her chest and neck is likely secondary to atrial contraction against the closed AV valves...
Source: Spontaneous Circulation - Category: Emergency Medicine Tags: Blog Posts Source Type: blogs