Evidence-Based Prehospital Diagnosis of Heart Failure


CarolinaFireJournal - By Bryan Beaver, MD and Brian Hiestand, MD
By Bryan Beaver, MD and Brian Hiestand, MD
10/26/2015 -

EMS receives a call for a 68-year-old male with shortness of breath.  Reported history includes coronary artery disease, heart failure, hypertension, COPD and diabetes.  On arrival, he is tachycardic, tachypneic and hypertensive to 186/101 with rales at bilateral lung bases, scattered wheezes, and 2+ pitting edema.   The question: why is this patient short of breath?  Is this acutely decompensated heart failure, a COPD exacerbation, acute coronary syndrome, pneumonia or pulmonary embolism?  How do we tell the difference?

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Introduction

Heart failure affects approximately one to two percent of the adult population with approximately five to 10 new cases per 1000 persons per year.   Though some studies suggest that admissions for a primary diagnosis of heart failure are declining, mortality at five years remains approximately 50 percent after symptom onset. 

The challenge to the provider is that a decompensated heart failure presentation can be confusing, with various signs and symptoms including dyspnea, respiratory distress, jugular venous distention (JVD), wheezing, rales, rhonchi, third heart sound (S3), and peripheral edema.  Patients can present with volume overload or volume depletion (too much furosemide), hypertensive or hypotensive.  This article will discuss those features of the history, physical exam, and initial diagnostic tests that are available in the prehospital setting will best help guide us toward or away from a diagnosis of heart failure.

Discussion

One approach to evaluation of a patient with possible decompensated heart failure considers the patient’s volume status and perfusion.   In this scheme a patient’s volume status can be either “wet” (volume overloaded) or “dry” (euvolemic or hypovolemic) and perfusion status can be either “warm” (normo- or hypertensive with signs of good peripheral perfusion) or “cold” (hypotensive with poor peripheral perfusion).  When these are considered together a patient falls into one of four categories:

  1. Warm and dry
  2. Warm and wet
  3. Cold and dry
  4. Cold and wet

The “warm and dry” patient in this scheme is very unlikely to have acutely decompensated heart failure.  Most patients — 85 percent or more — will present as “warm and wet,” maintaining peripheral perfusion, but dyspneic due to pulmonary congestion. Sometimes, this congestion can be due to total body volume overload.  Frequently, however, this is due to “afterload crisis” where the total body water may be within tolerance, but the afterload is too great to allow the impaired left ventricle to push the blood forward into the circulation. 

In another approach, JAMA’s “Rational Clinical Examination” series evaluated the value of history, physical exam findings, and diagnostic testing to differentiate heart failure from other causes of dyspnea.  If a patient with shortness of breath has a history of heart failure, myocardial infarction, or coronary artery disease, the odds are greater that the dyspnea is due to decompensated heart failure.  Likewise, the absence of those historical elements decreases the chance of heart failure exacerbation.   Unfortunately, acute heart failure can occur without a previous history, and patients with chronic heart failure can still have other reasons to be short of breath.

Similarly, if a patient complains of paroxysmal nocturnal dyspnea, orthopnea, or dyspnea on exertion, the chances that the symptoms are due to acute heart failure increase.  In regards to the physical exam, an S3 heart sound was the only physical exam finding shown to significantly increase the likelihood of heart failure. The S3 heart sound, also known as a “ventricular gallop,” is a low frequency sound occurring in early diastole.  Leg swelling, rales, and JVD occur in too many other disease states to be completely diagnostic of acute heart failure, although their presence does modestly increase the likelihood of heart failure as the origin of ongoing dyspnea.   

Conclusion

Returning to our original patient, he has a history of heart failure and has had worsening dyspnea on exertion for the past two days, both potentially predictive of a heart failure exacerbation.  Regarding the physical exam, he is hypertensive with good peripheral perfusion placing him into the “warm” category, and has signs that he is “wet” or volume overloaded identified by his rales and peripheral edema.  Putting these together, one could say it is likely the patient’s symptoms could be attributed to an acutely decompensated heart failure exacerbation.

By appropriately identifying patients with acutely decompensated heart failure exacerbations, initial treatment can then be started by EMS in the field.

Bryan Beaver, MD is an EMS/Disaster Medicine Fellow at Wake Forest Baptist Medical Center. Brian Hiestand, MD is Associate Professor of Emergency Medicine at Wake Forest Baptist Medical Center.
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