You could miss an MI due to an elder's pacemaker

ST elevation may be masked

A very sick elder with multiple chronic conditions presented to ED nurses at St. Joseph's Hospital and Medical Center in Phoenix with vague symptoms including shortness of breath. Her initial EKG revealed a paced rhythm.

"We recognized that there was more to her shortness of breath than her chronic obstructive pulmonary disease," says Rhyan Weaver, RN, BSN, CEN, clinical supervisor in the ED. "A complete assessment of her condition prompted us to try and capture her rhythm unpaced."

An anterior wall myocardial infarction (MI) was revealed. "Without diligent assessment and persistence in obtaining important diagnostic tests, we may not have captured the STEMI so quickly," says Weaver. "Relying solely on cardiac markers or classic signs of an MI could have taken hours, causing devastating damage to the myocardium."

Elders have age-related changes to the cardiovascular system, causing conduction abnormalities, and might require an implanted pacemaker, notes Weaver. This might mask ST elevation on the EKG, causing late identification of a myocardial infarction, she explains. "In any patient who is paced, the nurse must use his or her assessment skills to identify signs of an MI, since the EKG does not provide this information," says Weaver. To identify a serious condition, Weaver says look for pale or diaphoretic skin, chest pain, gastrointestinal discomfort, and the comment, "I just don't feel well."

Unfortunately, there is no proven way to capture a rhythm unpaced, says Weaver. This means you have to rely on other assessment methods such as chief complaint, past medical history, skin assessment, breathing patterns/effort, and diagnostic measures such as cardiac markers.

"This is why diagnosing a STEMI on a paced patient is so tricky," says Weaver. "The most important measurement, the gold standard EKG, is useless in this situation."

Atypical symptoms

Colleen Claffey, RN-BC, MSN, CEN, CPEN, nurse educator for the ED and critical care at Jackson North Medical Center in North Miami Beach, FL, says, "The elderly population commonly present with atypical symptoms, compounding the complexity of making a definitive diagnosis. Meticulous clinical assessment and history-taking become that much more important."

The older population will not necessarily report chest pain or shortness of breath. "Rather, feelings of fatigue, epigastric pain, back discomfort, or nausea and vomiting are much more common complaints," says Claffey.

An elderly woman recently reported profound fatigue and tightness across her shoulders to Jackson North's ED nurses. The patient had a dual chamber pacemaker and history of diabetes, and she was hypotensive and tachypenic. The cardiac team was notified, and a decision was made to take her emergently to the cardiac catheterization lab. "The patient was diagnosed with an inferior myocardial infarct and required stent placement," says Claffey. "In the case of an elderly patient with a pacemaker, keen assessment abilities and a proactive cardiovascular program is essential." (See clinical tip, below, on identifying cardiac risk factors.)

Clinical Tip

Use medication history to ID cardiac risk factors

A detailed medication assessment can identify risk factors that may reveal the need for a cardiac catheterization, says Colleen Claffey, RN-BC, MSN, CEN, CPEN, nurse educator for the ED and critical care at Jackson North Medical Center in North Miami Beach, FL.

"Antihypertensives, statins, or anti-dysrhthmics are good indicators in the patient's medications of cardiac risk factors," says Claffey. "Personal history risk factors include obesity, smoking, or large alcohol consumption."