Cardiovascular Critical Care I
Patient Case (Continued)
J.M.’s ECG results reveal no acute evidence of ST segment changes. However, the resident is still consider-
ing a diagnosis of ACS, given the patient’s shortness of breath and mild troponin elevation. Which statement
would be most accurate regarding the potential for other potential diagnoses?
J.M. has been experiencing intermittent bradycardia on telemetry. The team has consulted the cardiac elec-
trophysiology team. In the meantime, which statement most accurately reflects whether any other underlying
correctable/contributing causes can be addressed?
Abnormal impulse formation
Altered automaticity
Abnormal automaticity
Triggered activity—early or delayed
Reentry
Conduction block
Pathophysiology of Heart Disease 2011:xiv; BMJ 2002;324:662-5; BMJ 2002;324:415-8)
Etiologies of heart block (Box 3)
Box 3. Causes of Bradyarrhythmias
| • | CAD |
|---|---|
| • | Degenerative conduction disease |
| • | Drug induced |
| • | Electrolyte disturbances (particularly hyperkalemia) |
| • | Endocarditis |
| • | Myocarditis |
| • | Surgery (particularly cardiac surgery) |
| • | Tumors |
| • | Vagus nerve–mediated heart block |
CAD = coronary artery disease.