Echocardiography update for primary care physicians
A review article written by cardiologists from Hong Kong and China summarizes the latest developments in echocardiography and outlines its general usage across a wide spectrum of disorders. [Hong Kong Med J 2020;26, doi: 10.12809/hkmj198080]
“Patients with heart diseases are increasingly likely to present to primary care physicians [PCPs] as their first point of care or for a follow-up examination: up to 15 percent of coronary heart disease patients are treated exclusively by PCPs,” wrote the authors. [Scand J Prim Health Care 2002;20:10-15]
The treatment of patients with cardiovascular (CV) diseases almost invariably involves the use of echocardiography as a means of initial and follow-up investigation. Echocardiography does not involve radiation and may be used as a point-of-care diagnostic tool in both outpatient and inpatient settings, where it improves outcomes in some patients and may identify otherwise undiagnosed valvular heart diseases. [J Am Coll Cardiol 1999;33:164-170; Eur Heart J 2016;37:3515-3522]
With recent technological developments having expanded the use of echocardiography dramatically, the authors have sought to review contemporary literature on clinical indications and emerging technologies of echocardiography and to provide a summary for PCPs.
Echocardiography is indicated for evaluating symptoms or conditions that are likely to be of cardiac aetiology, including chest pain, shortness of breath, palpitations, transient ischaemic attack, stroke, or peripheral embolic event.
“For evaluation of acute chest pain with suspected myocardial ischaemia/infarction and non-diagnostic electrocardiogram [ECG], resting transthoracic echocardiography [TTE] is appropriate. The absence of regional wall motion abnormality on 2D TTE during chest pain virtually excludes acute MI, with a sensitivity of 93 percent for any infarct and 100 percent for ST-elevation MI,” wrote the authors. [Circulation 1991;84(3 Suppl):I85-I92]
Shortness of breath is a common symptom among patients presenting to emergency departments and PCPs, and its differential diagnoses include CV disease, lung disease, anaemia, obesity, and deconditioning. “When heart failure [HF] is suspected, TTE is mandatory to confirm or exclude the diagnosis; to quantify chamber volumes, systolic and diastolic function, and wall thickness; and to identify the aetiology of HF (eg, cardiomyopathy, valvular disease, or prior MI),” wrote the authors.
Patients who have undergone chemotherapy or radiotherapy are at risk of developing HF, and baseline echocardiography with regular follow-up assessments is required, as earlier detection can potentially reverse myocardial dysfunction before irreparable damage occurs. [Am Coll Cardiol 2010;55:213-220] “Assessment of the global longitudinal strain is useful for detecting chemotherapy-related cardiotoxicity, and is better than the assessment of left ventricular ejection fraction,” advised the authors. [J Am Soc Echocardiogr 2014;27:911-939]
“Echocardiography is considered appropriate when heart disease or structural abnormality are suspected on prior testing including chest X-ray, ECG, or cardiac biomarkers, whether the patient is symptomatic or not,” summarized the authors. “Generally, echocardiography is appropriate for initial diagnosis when there is a change in clinical status or when its results are anticipated to change treatment.”
According to the American College of Cardiology, appropriate echocardiography “likely contributes to improving patients’ clinical outcomes”, while inappropriate echocardiography may be “potentially harmful to patients and generate unwarranted costs to the healthcare system”. [J Am Soc Echocardiogr 2011;24:229-267]
“Echocardiography will continue to grow as a core clinical investigation for a wide spectrum of disorders, and its relevance to PCPs cannot be overstated,” concluded the authors.