Cardiovascular Evaluation & Monitoring Flashcards

Which lead configuration is considered the best single lead for detecting ST-segment changes during continuous cardiac monitoring?

Answer: Lead V5

Lead V5 is the most sensitive single lead for detecting ST-segment changes, particularly myocardial ischemia involving the lateral wall.

A patient's arterial blood gas shows pH 7.28, PaCO2 52 mmHg, HCO3 24 mEq/L. What is the primary acid-base disturbance?

Answer: Respiratory acidosis

The elevated PaCO2 with normal bicarbonate indicates primary respiratory acidosis without metabolic compensation.

During 12-lead ECG acquisition, what is the recommended paper speed for standard recording?

Answer: 25 mm/sec

The standard ECG paper speed is 25 mm/sec, making each small square represent 0.04 seconds.

Which hemodynamic finding is most consistent with cardiac tamponade?

Answer: Pulsus paradoxus >10 mmHg

Pulsus paradoxus greater than 10 mmHg — an exaggerated fall in systolic BP during inspiration — is a hallmark finding of cardiac tamponade.

On a cardiac monitor, artifact mimicking ventricular fibrillation is most commonly caused by which of the following?

Answer: Patient shivering or muscle tremor

Shivering or skeletal muscle tremor produces high-frequency artifact that can closely resemble the chaotic baseline of ventricular fibrillation.

What does a prolonged QTc interval (>500 ms) primarily indicate in the context of ECC?

Answer: Increased risk of torsades de pointes

A QTc greater than 500 ms significantly increases the risk of torsades de pointes, a potentially fatal polymorphic ventricular tachycardia.

When auscultating heart sounds, an S3 gallop in an adult patient most commonly suggests:

Answer: Ventricular volume overload or heart failure

An S3 gallop in adults indicates rapid ventricular filling against a non-compliant ventricle, most commonly associated with heart failure or volume overload.