Certified Cardiographic Technician (CCT) Practice exam

Digitalis is the medication most likely to produce a false positive result during an exercise stress test. This is primarily due to its effects on the heart's electrical system. Digitalis can cause characteristic changes in the electrocardiogram (ECG) that may lead to misinterpretation of the test results. For instance, it can cause ST segment changes that might mimic ischemia, even when the heart is actually normal. The other medications listed do not have the same potential for creating misleading results in the context of an exercise stress test. Nitrates generally do not impact the stress test results in a way that would create false positives, as they primarily work by dilating blood vessels and reducing myocardial oxygen demand. Propranolol, a beta-blocker, tends to blunt heart rate response during exercise, which can actually help prevent false positives. Meanwhile, calcium channel blockers also do not typically lead to misleading ECG changes during stress testing. Understanding the specific actions of each medication and their influences on cardiac function and ECG readings is crucial for accurate interpretation of exercise stress tests and avoiding false positives.