Mild congestive heart failure may not even be noticeable to the person who has it, even when they are exercising.

“Usually if the mild congestive heart failure comes on very gradually and it is only mild diastolic CHF, then it may not be noticeable or only noticeable with very rigorous exertion,” or activity that’s more than usual for the individual, says Dr. Sameer Sayeed, a cardiologist at ColumbiaDoctors of Somers, NY.

So if you’ve always gone out every morning to leisurely walk your dog for half a mile, and all along your diastolic heart function is getting a little worse such that it’s in the range of mild heart failure — you probably won’t be suddenly panting at the end of that half mile.

Diastolic CHF: The heart is stiff, not relaxing properly. It does not fill up with the right amount of blood to be pumped out.

Thus, less blood is pumped out, meaning less oxygen throughout the body.

“If it is more severe diastolic CHF, then it may be a more acute and rapid decline,” says Dr. Sayeed.

“If it is systolic CHF and the ejection fraction [pumping force] goes below 40 percent, then the symptoms may come on more rapidly and with minimal exertion like [walking] a block or two or one flight of stairs.”

Systolic CHF: decreased pumping function. The heart’s “squeeze” is not optimal.

Dr. Sayeed explains, “The fatigue is usually most noticeable with exertion, particularly stairs and inclines, and the patient may suddenly report not being able to go up stairs or a hill or do competitive sports, etc.

“Symptoms won’t be so apparent at rest or with things like golf or easy activities where it may go unnoticed.”

If you’ve been working out all along, it’s smart to keep a record of your key workloads, which may be measured in amount of resistance, distance, speed or time.

As we age, these values will gradually decrease, e.g., your fastest one-minute run on a treadmill may be 12 mph at age 50, but 11.5 mph at age 55. This is normal decline.

If a performance deficit, however, is suspiciously rapid with no explanation (such as recent injury), then this warrants a medical evaluation.

Congestive heart failure can be one of numerous causes of an inexplicable deficit in aerobic stamina or strength.

Dr. Sayeed performs echocardiograms and stress tests at the Midtown Manhattan and Westchester offices at Columbia Doctors. He is also trained in cardiac CT imaging.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer. 
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