Cardiomyopathy

By Dr. Lawrence Earl, National Academy of DOT Medical Examiners

Introduction

Recently FMCSA has stated that it no longer “endorses” the medical examiner handbook, a publication many examiners have used as their “bible” for guidance regarding commercial driver exams. The truth is, it is out of date. As are many of the resources provided by FMCSA. Most of the expert panel reports in current publications are at least 10 years old.

The Cardiovascular Recommendation tables are a widely used resource by examiners who would otherwise find it impossible to remember all the recommended tests, measurements, cutoff levels, and waiting periods for the myriad cardiovascular conditions encountered during the commercial driver exam.

Even the straightforward blood pressure table we used to rely on from the “old form” has been taken down and we’ve debated whether to stick to that or progress through the JNC 7 – 8 – 9 recommendations. But these are based on the medical expert panel report from 2002 and were last “officially” updated in 2009.

Case Example

“I have a driver with hypertrophic cardiomyopathy, and it is considered hereditary. He never had any symptoms but because they found it in his family all of his family had workups. His Cardiologist released him to drive commercially. His EF fraction is 55% and the nuclear stress test was negative for ischemia.

The FMCSA examiner handbook (I know it is not endorsed at this time) advises non-clearance for DOT due to the elevated risk of sudden death from this condition. What is your opinion on this?”

In 2015, the medical review board published some updates to several cardiovascular conditions based on more current best practices. The medical expert panel recommends these guidelines be updated to reflect current thinking that not all individuals with hypertrophic cardiomyopathy are at risk for sudden incapacitation or death. Specifically, the panel recommends that individuals who meet all the following criteria are at low risk and may be certified to drive:

No history of cardiac arrest
No spontaneous sustained VT
Normal exercise BP (e.g., no decrease at maximal exercise)
No non-sustained VT
No family history of premature sudden death
No syncope
Left ventricular (LV) septum thickness <30mm

The MEP noted that low-risk individuals must be followed closely for changes in risk status.

The MEP recommends changes to the text explaining the criteria that define who should not be certified to drive a CMV, relative to those individuals with idiopathic dilated cardiomyopathy who do not have symptomatic HF. The current guidelines state that individuals with ventricular arrhythmia who present an LVEF<50% be precluded from certification. The MEP recommends that these criteria be changed to the following: