Cardiac Stress Testing Protocols Flashcards

A patient is referred for stress testing with a resting heart rate of 110 bpm. What is the most appropriate initial management before proceeding?

Answer: Investigate and treat the underlying cause of tachycardia before stress testing

Resting sinus tachycardia >100 bpm is a relative contraindication to stress testing; the cause should be identified and treated before proceeding.

What is the significance of ST-segment elevation (not depression) appearing in leads without Q waves during an exercise stress test?

Answer: Indicator of severe transmural ischemia or coronary spasm requiring immediate attention

Exercise-induced ST elevation in leads without Q waves indicates severe transmural ischemia or vasospasm and requires immediate test termination.

Which MET level achieved on exercise stress testing is generally considered to indicate good functional capacity and a favorable prognosis?

Answer: ≥10 METs

Achieving ≥10 METs is associated with excellent prognosis regardless of ST-segment changes, as it reflects good cardiorespiratory fitness.

A patient on a treadmill stress test develops a new 2 mm ST depression at 7 METs that fully resolves within 2 minutes of recovery. Using the Duke Treadmill Score formula (Exercise time − 5 × ST deviation − 4 × angina index), this would place the patient in which risk category?

Answer: Intermediate risk (score −10 to +4)

With approximately 7 minutes exercise time and 2 mm ST depression without angina: 7 − (5×2) − (4×0) = −3, which falls in the intermediate-risk range (−10 to +4).

During a vasodilator pharmacological stress test, a patient develops complete heart block. What is the correct immediate intervention?

Answer: Administer aminophylline IV and place the patient supine

Aminophylline reverses adenosine receptor-mediated complete heart block; the agent's short half-life also means the block typically resolves rapidly with antagonism.

Which stress testing parameter is most predictive of cardiac mortality independent of angiographic findings?

Answer: Exercise capacity in METs

Exercise capacity measured in METs is one of the strongest independent predictors of cardiac and all-cause mortality across multiple studies.

An 85-year-old patient cannot exercise adequately for treadmill testing and has a documented theophylline allergy. Which pharmacological stress agent is most appropriate?

Answer: Dobutamine — acts via adrenergic receptors, unaffected by adenosine antagonism or theophylline allergy

Dobutamine works through beta-adrenergic stimulation rather than adenosine receptor pathways, making it the appropriate agent when adenosine-based agents are contraindicated or when aminophylline reversal is unavailable due to allergy.