Case continued: Enroute to the ER, the patient's acute symptoms had been relieved by the prompt action of the emergency care personnel. Vital signs had stabilized, his chest pain was relieved by nitroglycerin, and breathing was made easier by the increased oxygen flow.
Arriving at the hospital emergency room, the patient was immediately surrounded by medical professionals including critical care nurses, ER physicians, and others. Blood was drawn and sent to the laboratory (along with the initial blood drawn by the EMTs,) for STAT (immediate!) analysis of cardiac serum markers, a CBC and electrolytes. A chest radiograph (x-ray) and echocardiogram were also performed. The patient's EKG findings were carefully reviewed by the ER physician and the on-call cardiologist was summoned.
View Cardiac Conductions System and Understanding an ECG (below) and answer the following questions:
- 20. What is an electrocardiogram?
- 21. What is the natural pacemaker of the heart?
- 22. Trace the electrical conduction pathway through the heart.
- 23. What does the P wave correspond to in an ECG?
- 24. On an ECG tracing, when does atrial contraction or systole occur?
- 25. What does the QRS wave correspond to in an ECG tracing?
- 26. The ST segment in an ECG corresponds to what action in the heart?
- 27. What does the T wave correspond to in an ECG tracing?
Initial Diagnostic Results were reported from the laboratory.
- 28. How does measuring the level of cardiac enzymes help detect a myocardial infarction (MI)?
- 29. Why are Mr. Dixon's cardiac enzyme levels normal or only slightly elevated, even though it appears he has just experienced an acute MI?
- 30. What health care professional is responsible for determining cardiac enzyme levels?
- 31. Which cardiac enzyme is the preferred marker for myocardial injury?
Mr. Dixon was diagnosed with having a myocardial infarction. He was admitted to the hospital's coronary care unit (CCU) and carefully monitored by specially-trained coronary care nursing personnel. In patients with an AMI, the risk of sudden death is usually within the first 24 hours of the initial attack.
Review Myocardial Infarction. (Review slides 2-6)
View Heart attack (watch the portion of this video explaining a heart attack) (below) and answer the following questions:
- 32. What is a heart attack?
- 33. List symptoms of a heart attack.
- 34. How may heart attack symptoms differ in women?
- 35. What causes blockage of coronary arteries? What symptom may this narrowing of arteries cause?
- 36. What complication might happen if the hard shell of the plaque ruptures?