Syncopation and Strain

EMS is inbound with a 50 yo male patient. The patient reports shortness of breath and diaphoresis. He was feeling a bit lightheaded and passed out for approximately 30 seconds prior to calling 911. The patient denies other trauma or recent illness. The patient has noted some increasing dyspnea on exertion during the past week. The onset of symptoms occurred without warning or provocation. EMS acquires a 12 lead ECG. A nurse onscene advised that the patient was hypotensive and "clammy" following the syncopal episode.

PMHX:
Hypertension
Dyslipidemia
Appendectomy

Vitals: 
BP: 110/70
P: 131
R: 22
Sp02: 95%

12 Lead ECG:

12 Lead ECG Interpretation and Discussion: 
The rate is tachycardic at approximately 140 beats per minute and regular. The RSR' morphology and duration of the QRS complex in V1 suggests the presence of a right bundle branch block. The terminal R wave in V1,  the slurred S wave in V6, and the inverted T waves in aVL and V1 are expected in the setting of a bundle branch block. It is difficult to discern p waves though there may be a retrograde P waves present in leads III and V2. Tachycardia and right bundle branch block suggest the presence of "right heart strain."

Final interpretation:
Supraventricular tachycardia, rate of 140/min. Right bundle branch block. Electrocardiographic evidence of right heart strain.

Emergency department course:
Supplemental oxygen was administered. A bedside echocardiogram revealed a dilated right ventricle. There was no pericardial effusion. A portable chest xray was without any obvious abnormality. The patient received an infusion of unfractionated heparin and underwent multi-detector CT angiography of the chest. The patient was found to have bilateral, segmental pulmonary embolisms.

Pulmonary embolism:
A pulmonary embolism, or "PE", may be extremely difficult to diagnose. Patients present with a wide variety of symptoms, and not all pulmonary embolisms result in persistent vital sign abnormalities. Providers should have a low suspicion for pulmonary embolism in patients with tachypnea, tachycardia, and pleuritic chest pain. Syncope is a concerning complaint and can be effectively evaluated with a 12 lead electrocardiogram. In this case, the syncope resulted from the patient's clot burden. A sub-massive pulmonary embolism can reduce preload and compromise cardiac output.

Syncope? Get the 12 lead!