Special Considerations for Cardiovascular Disease: Valvular Heart Disease and Peripheral Artery Disease

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This chapter presents background and special considerations related to exercise testing, prescription, and progression for individuals with valvular heart disease (VHD) and for individuals with peripheral artery disease (PAD). The first section of this chapter addresses VHD. The case study presented outlines the diagnosis of an older woman with aortic stenosis and follows her through her recovery during 12 weeks of cardiac rehabilitation. This case study provides guidance for the design of a progressive aerobic conditioning and eventual resistance training program with a primary goal of return to activities of daily living for an individual with VHD.

VALVULAR HEART DISEASE

Case Study 13-1

Mrs. Case Study-Valve

Mrs. Case Study-Valve is a 73-year-old woman weighing 65 kg (143 lb) with a height of 1.6764 m (5 ft 6 in) tall. She has a 2-month history of feeling light-headed while carrying laundry up one flight of stairs at home. This occurs less often when not carrying anything upstairs. She has not lost consciousness during any of these episodes, nor has she had chest pain or unusual shortness of breath. However, she is not physically active outside of her activities of daily living around her home. She has no history of high cholesterol, smoking, or significant family history for coronary artery disease (CAD). Her blood glucose is slightly elevated with a glycolated hemoglobin (HbA1c) of 5.9 and a long history of hypertension that currently is well controlled with a diuretic and angiotensin-converting enzyme (ACE) inhibitor.

She saw her primary care physician (PCP), who noted a 3/6 systolic murmur. She was asked to follow up with an echocardiogram and routine treadmill testing to better evaluate her symptoms.

She underwent exercise stress testing on a treadmill using a Cornell protocol. Her resting electrocardiogram (ECG) demonstrated normal sinus rhythm, normal heart rate, normal axis, and no concerning acute ST changes. She was able to complete 8 minutes and 40 seconds (speed of 2.5 mph with 12% grade). Her heart rate increased from 67 bpm at rest to 127 bpm (86% of predicted maximal capacity) at the peak workload. Her blood pressure (BP) initially increased from 132/80 mm Hg at rest to 140/78 mm Hg at 3 minutes and then fell to 136/74 at 6 minutes and 118/68 at the peak workload. Her ECG had no concerning changes, but between 6 minutes and peak effort, she began having frequent, unifocal premature ventricular contractions (PVCs), which resolved within 2 minutes of recovery. She denied chest pain or palpitations but complained of light-headedness that correlated with her falls in systolic BP during testing. This also resolved within a couple minutes of exercise (Table 13.1).

Table 13.1

Treadmill Graded Exercise Test Results for Mrs. Case Study-Valve

Pretest Data

Protocol: Cornell

Resting HR: 67 bpm

BP: 132/80 mm Hg

2 min Stages	Speed (mph)	Grade (%) and Estimated METs		HR (bpm)	BP (mm Hg)
0	1.7	0	2	81
0.5	1.7	5	3	95	140/78
1.0	1.7	10	5	109	136/74
1.5	2.1	11	6	121
2.0	2.5	12	7	127	118/68
Recovery Phase Immediately: HR —; BP — 2 min: HR: 85; BP: 132/78 mm Hg 5 min: HR: 70; BP: 130/82 mm Hg

HR, heart rate; BP; blood pressure.

The patient stopped at 8 minutes and 40 seconds (stage 2.0) due to light-headedness. She had a follow-up echocardiogram 2 days later which revealed normal biventricular, systolic function (left ventricular ejection fraction [LVEF] about 55%–60%), mild-to-moderate left ventricular hypertrophy (LVH), moderate-to-severe aortic stenosis, and no other issues noted. Due to a symptomatic stress test and significant valvular disease, she was referred for aortic valve replacement surgery.

After a successful surgery and discharge from the hospital 5 days later, Mrs. Case Study-Valve was referred to a traditional cardiac rehabilitation program. She attended monitor exercise sessions three times a week for 12 weeks and was given a weekly home exercise prescription to follow on the off days from cardiac rehabilitation. Her exercise program began with building her endurance and incorporating gentle stretching exercises. For the first week, she walked on the treadmill at a pace she could comfortably sustain for 10 minutes without symptoms. The workload was 1.5 mph or 2.0 metabolic equivalents (METs). Each successive week, she was progressed by no more than 5 minutes and 0.5 METs each week (Table 13.2). She also performed a total body, gentle stretching routine without pain and was encouraged to stretch daily after her aerobic exercise sessions.

Table 13.2

Progressive Aerobic Training Program for Mrs. Case Study-Valve during Cardiac Rehabilitation

Week	Treadmill Workload (METs)	Treadmill Time (min)
1	2.0	5–10
2	2.3	15
3–4	2.6	20–25
5–6	3.2	25–30
7–8	3.5	30
9–10	3.8	30–35
11–12	4.0	30–40

To gain upper body conditioning, 1 month after surgery she began using a recumbent stepper for 5–10 minutes in addition to the treadmill exercise. Her heart rate and MET level were matched to heart rate and MET level on the treadmill. For upper body strength, 2 months after surgery she began a strength training routine for the major muscles of the arms and trunk, including biceps curls, lateral shoulder raises, standing triceps kickback extensions, and standing dumbbell rows (Table 13.3). Muscle strength was assessed for each exercise using the 10-repetition maximum method. She continued to progress in her aerobic, flexibility, and strength training routine through the end of cardiac rehabilitation. At that point, she graduated and maintained her exercise routine at home.

Table 13.3

Progressive Resistance Training Program for Weeks 13–24 for Mrs. Case Study-Valve

Week	Day 1 (% RM, Sets × Repetitions)	Day 2 (% RM, Sets × Repetitions)
8	60, 1 × 12	60, 1 × 15
9	70, 2 × 10	70, 2 × 12
10	80, 2 × 10	80, 2 × 12
11	70, 3 × 10	1-RM testing
12	60, 2 × 12	60, 2 × 15

Description, Prevalence, and Etiology

VHD is any disease or abnormality of a single heart valve or any combination of the four valves. The most prevalent valvular diseases are those of the aortic and mitral valves due to the higher pressure on the left side of the heart. Tricuspid and pulmonary valve diseases are much less common (4). Over 5 million Americans are diagnosed with VHD each year (15), and approximately 10% of people older than 75 years of age have some form of VHD (15). VHD can be congenital or acquired later in life; however, most cases of VHD are the result of aging (15).

Heart murmurs (the sound of valve dysfunction) can be detected with a stethoscope, but an echocardiogram is the primary imaging tool used to diagnose VHD. Valvular diseases are typically classified as a leaky valve (regurgitation) or the inability of a valve to completely open (stenosis). Over time, both regurgitation and stenosis can reduce cardiac output and lead to cardiac hypertrophy and, eventually, myocardial dysfunction or heart failure (6). Exercise training has not been shown to improve valve function but can improve peripheral adaptations and functional capacity in patients with VHD (6).

Preparticipation Health Screening, Medical History, and Physical Examination

Evaluation of VHD will usually happen before the patient is referred to cardiac rehabilitation or a supervised exercise program. However, the exercise professional should be familiar with the most common symptoms of VHD. Symptoms originating from VHD can vary dependent on several factors: the specific valve(s) involved, the condition and severity of the valve(s), and the presence of other comorbidities.

Symptoms of VHD may be more subtle at the onset and can be difficult to discern through an initial patient interview, which can lead to multiple differential diagnoses and a “shotgun” approach to testing. Gradually, if not diagnosed correctly in the early stages, symptoms can worsen considerably and lead to more debilitating conditions such as heart failure.

During exercise, many of the symptoms listed in Box 13.1 may be present. The specific symptoms will vary depending on which valve is involved and the degree of impairment. Normal mild-to-moderate valve disease may not impair the ability to exercise, but progression toward more severe VHD can result in multiple abnormal conditions during exercise (Table 13.4).

Box 13.1	Common Symptoms of Valvular Heart Disease
Shortness of breath
Dyspnea on exertion
Fatigue
Palpitations
Chest discomforts
Near syncope
Syncope
Unexplained coughing
Swelling in lower extremities

Table 13.4

Signs and Conditions Related to the Dysfunction of Specific Valves

Conditions	Mitral Stenosis	Mitral Regurgitation	Aortic Stenosis	Aortic Regurgitation
Reduced CO	X		X
Exertional hypotension	X		X
Exertional syncope	X		X
Inadequate MO₂	X		X
Chest discomfort	X		X
ECG changes		X	X	X
LVH/false positive result		X	X	X
Diastolic dysfunction			X	?
Systolic dysfunction		X		X
Ventricular ectopy		X	X	X

CO, cardiac output; MO₂, myocardial oxygen consumption.

Although this chapter does not go into detail on the different heart sounds (heart murmurs) related to significant VHD, it is in the best interest of the clinical exercise professional to be able to distinguish between a normal and abnormal heart sound and to be able to communicate findings to a qualified medical professional.

In many cases, if a heart murmur is detected and if symptoms are suggestive of a possible heart valve disorder, an ultrasound (echocardiogram) of the heart may be ordered. The echocardiogram will look at the structure and function of the heart muscle and valves and provide valuable information to the physician about the best plan of care for the patient.

Case Study 13-1 Quiz:

Preparticipation Health Screening, Medical History, and Physical Examination

1. What intensity for cardiovascular exercise would you suggest for this patient if medical management is decided on?

2. Assuming this patient continues with medical management for aortic stenosis, would you perform regular, nonimaging, exercise stress testing to evaluate for detection of CAD? If so, why?

Exercise Testing Considerations

Exercise testing is often a valuable tool to evaluate overall prognosis of individuals with VHD. Specifically, it can measure the degree of physical impairment from symptoms, the thresholds of abnormal hemodynamic responses, the thresholds for arrhythmias, the efficacy of medical management, and the need for surgeries and interventions.

The type of exercise stress testing must be carefully selected and specific to medical needs. Issues such as LVH and false positive ECG changes suggestive of ischemia can result from VHD when performing exercise testing (Table 13.5).

Table 13.5

Types of Exercise Testing and Quantifiable Data

Type of Testing	Prognosis/ Capacity	Hemodynamic Response	Arrhythmia	Symptom Threshold	O₂	Ischemia
Routine exercise ECG only	X	X	X	X
Stress nuclear imaging	X	X	X	X		X
Stress echocardiogram	X	X	X	X		X
Cardiopulmonary	X	X	X	X	X

O₂, volume of oxygen consumed per unit time.

Endpoints for exercise testing with those suffering from VHD are generally the same as noted in ACSM’s Guidelines for Exercise Testing and Prescription, 10th edition (3). Specifically for this population, look for the onset of serious arrhythmias, excessive ST depression on ECG, plateau or drop in systolic BP with increased work rate (especially in presence of symptoms or ECG changes), slowing of heart rate with increased work rate, or excessive increase in systolic/diastolic BP (11).

Case Study 13-1 Quiz:

Exercise Testing Considerations

3. The patient’s systolic BP fell during exercise testing, from 132/80 to 118/68 mm Hg at peak exercise. Would this be considered a relative or absolute indication for terminating exercise testing?

4. Would the Bruce protocol have been appropriate for this patient? Why or why not? Name another protocol you could select for this patient and justify your answer.

5. What precaution(s) need to be taken for a patient post–valve-replacement surgery for one repetition maximum (1-RM) testing to be safe?

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