Fix the Rate First ?

CASE PRESENTATION:
Providers respond to a 68 yo female with a sudden onset of paroxysmal nocturnal dyspnea. The patient reports slight dyspnea on exertion for the past few weeks and endorses a mild, non productive cough. The patient speaks in 2-3 word sentences and appears in severe respiratory distress. The patient denies chest discomfort, nausea, vomiting or fever. The patient is in severe respiratory distress and is profoundly diaphoretic. Another paramedic provider onscene diagnoses SVT and readies adenosine for administration.

EXAM:

BP:     220/120
P:        168
R:        40
Spo2:  88%


12 LEAD ECG:

12 LEAD ECG ANALYSIS:

There is a supraventricular tachycardia. P waves are difficult to discern but the QRS complexes are narrow and occur at regular intervals. Diffuse repolarization abnormalities in the form of biphasic T waves are present in the inferior leads. There is no obvious ST segment elevation.

TREATMENT:

High flow oxygen is administered and an intravenous line is inserted. The senior paramedic recommends against adenosine administration. A total of 1.2 mg of nitroglycerin is administered sublingually. 324 mg of aspirin is administered. As the patient is prepared for transportation, CPAP is started at 10 cm H20. The patient experiences rapid improvement and the hypoxia resolves. A repeat ECG shows sinus rhythm with some lateral ST segment depression. Vital signs following CPAP and NTG are as follows: BP: 180/100, P: 110, R: 22, Sp02: 100%. A chest xray shows cardiomegaly and bilateral opacities consistent with pulmonary edema are present.

DISCUSSION:

Though fixing a fast heart rate can reduce ischemia, it is important to consider the underlying cause of a dysrhythmia. Administration of adenosine could convert this ECG but the SVT is very likely due to the catecholamine surge that accompanies acute pulmonary edema. A reduction in cardiac output and afterload results in improved oxygenation, reduced work of breathing, and resolution of the supraventricular tachycardia. Following a hospitalization for acute heart failure, the patient was discharged to home on an aggressive medical regimen targeted at maintaining an acceptable blood pressure. The prehospital application of CPAP is consistently linked to a reduced endotracheal intubation and improved mortality.

Non Sustained VT: Making a Lasting Impression!

Putting on the Pressure

A 60 yo male presents to EMS with several hours of chest pressure and diaphoresis. A 12 lead ECG is obtained following a 10 beat run of non sustained ventricular tachycardia. Despite the EMT's excitement at "firing up the paddles," the paramedic administers 324 mg of aspirin and prepares for transport to the nearest facility capable of percutaneous coronary intervention. Your partner informs you that the monitor discerns the presence of a paced rhythm. The patient has no previous medical history.


12 LEAD ECG:

12 LEAD ECG Analysis:

A sinus rhythm is present and the rate is regular. Diffuse and concerning ST segment changes appear in this tracing. First, pathologic ST segment elevation occurs in leads V2, V3 and V4. Q waves also appear throughout the tracing. The monitor misinterprets the ischemic Q wave as a pacer spike. The QRS is narrow, so an interventricular conduction delay is less likely responsible for the "false pacer" call. Reciprocal changes appear in lead aVF. There is minimal J point depression in lead III and V6. The baseline is also irregular.


12 Lead ECG Interpretation: 

Sinus rhythm, anterior wall ST segment myocardial infarction.

Comments:

• It is difficult to discern the location of the anatomic lesion based upon this ECG. The large ST segment elevation in the precordial leads suggests involvement of the LAD. The findings of lateral wall ischemia could implicate the circumflex as well. 
• The run of VT was likely due to ventricular irritability. Remember that the most devastating complications of anterior wall ischemia are lethal dysrhythmia and cardiogenuc pulmonary edema 
• Pathologic Q waves generally follow a few rules: (1) larger than a third of the corresponding R wave or (2) measure in excess of 0.03 seconds. Q waves that accompany poor R wave progression are more likely to indicate ischemia.