Advances in our understanding of chronic diseases have led to improvements in the treatment of heart disease, a once lethal and highly debilitating illness. Unfortunately, chronic conditions often coexist with psychiatric illness. Thus, an understanding of the pathophysiology and treatment of chronic disease is crucial to meaningful and high-quality psychiatric care. One such chronic illness that affects mental health is heart disease. This article reviews the fundamentals of heart disease (ie, what it is, who it affects, how it is treated, and how it affects the psychiatric care of patients) to serve as a guide for psychiatric clinicians who care for patients with heart disease.
What Is Heart Disease?
The heart is the major organ of the cardiovascular system, which, in combination with an intricate network of arteries, veins, and capillaries, plays the major role of delivering blood to the various organs and tissues of the body. The heart is composed largely of muscle and connective tissue, and it is divided into four chambers: the left atria, the right atria, the left ventricle, and the right ventricle. Blood, which flows through the cardiovascular system, delivers oxygen and nutrients to tissues and organs, as well as transports waste and metabolic products to organs for excretion. Blood enters the right atrium, then flows through the tricuspid valve into the right ventricle, where it is pumped to the lungs. In the lungs, blood is enriched with oxygen while carbon dioxide is released and removed from the body. Blood then returns to the heart via the left atrium, moves through the mitral valve, and into the left ventricle. From there, blood is pumped to the coronary arteries (that deliver blood to the heart itself). Blood then flows through the aorta, and through a system of arteries, veins, and capillaries before returning to the heart and repeating the cycle. This process relies on the synchronized firing of nerves in the heart to ensure proper pumping of blood to optimize blood flow.
Heart disease is the term used to describe any disease process that adversely affects the efficiency of the heart's pumping of blood. Interruptions can occur in any part of the process but commonly involve blockage in blood flow to the heart itself via atherosclerosis, interruption in electrical activity (leading to arrhythmias), damage to the muscular or connective tissues that effect the mechanical actions of the heart muscle, or damage to the heart valves.
One common consequence of heart disease is congestive heart failure (CHF). CHF occurs when the heart fails to pump sufficiently (ie, when its ejection fraction [EF], which is the percentage of blood sent from the ventricles to the body after each beat, is reduced). If a person's EF dips below 50%, an insufficient amount of blood is delivered to the organs and tissues of the body, thereby resulting in a myriad of complications.1 CHF can be caused by either impaired relaxation of, or increased stiffness of the heart muscle, both of which cause backup of blood and fluid into the lungs and other tissues, resulting in edema and difficulty breathing.
Who Suffers from Heart Disease?
Heart disease is one of the most common chronic diseases; it affects tens of millions of adults in the United States and is one of the most common causes of death.2 Arrhythmias are also common; one type, atrial fibrillation (AF), affects about 6 million adults.2 Coronary artery disease (CAD) occurs in more than 15 million people in the US, 6.5 million people suffer from CHF, and 85.7 million are afflicted by hypertension.2
Heart disease accounts for one-fourth of all deaths in the US. Roughly one-half of those deaths are due to CAD, 9.1% are due to high blood pressure, and 8.5% are a result of CHF.3 Despite a historical trend of increased rates of death due to heart disease in the 1900s, the number of deaths related to heart disease has declined recently. Each year, about 525,000 people suffer their first heart attack (myocardial infarction [MI]), and 210,000 people have a recurrent MI.3 Thus, although the mortality rate of heart disease has declined over the past few decades, it continues to be a significant cause of morbidity and mortality in adults.
Several risk factors for heart disease have been identified. The incidence of heart disease increases with age. Men are more likely to develop CAD at an earlier age than women.2 Postmenopausal women are more likely to develop CAD than premenopausal women. Diabetes (a disease related to the inappropriate regulation of blood sugar in the body, which increases the risk of developing heart disease), hypertension, and high cholesterol also increase the risk for heart disease. In addition, several behaviors and environmental factors are associated with the development of heart disease. Cigarette smoking and exposure to second-hand smoke increases risk of death by 3-fold.2 Having overweight (body mass index [BMI] >25.0 kg/m2) or obesity (BMI >30 kg/m2) increases risk of CHF, arrhythmias, and CAD.2 In general, inactivity, stress, excessive alcohol consumption, and unhealthy nutritional habits are also associated with cardiovascular problems.
How Does One Develop Heart Disease?
Heart disease results from a variety of disease processes. Conditions such as hypertension or the development of cholesterol-filled plaques in the walls of the coronary arteries lead to interruptions in blood flow to the heart. Reduction in blood flow to the heart can occur over time with CAD, or can occur suddenly and dramatically and result in MI. Both the gradual reduction in blood flow to the heart and the consequences of an MI can lead to a chronic deficiency in the heart's ability to pump blood that can and result in CHF.4
Interruption of the heart's electrical activity (ie, arrhythmias) related to advancing age, sex, genetic factors, drugs, and medications can also lead to heart disease and CHF.4 If left untreated, arrhythmias can lead to CHF and death.
How Is Heart Disease Treated?
An important first step in the treatment of heart disease is identification of known risk factors, behaviors, or environmental factors that can be reversed. Although treatment of already developed heart disease is important, clinicians who provide psychiatric care can play a critical role in reversal or prevention of certain health behaviors associated with development or worsening of heart disease. Thus, maintaining normal blood pressure, increasing physical activity, and achieving a healthy weight is important. Cessation of smoking is critical to reducing the development of heart disease and the risk of complications, and a variety of therapies (including nicotine-replacement therapies or use of medications, such as varenicline, to reduce cravings of smoking) can be employed. The benefits of smoking cessation include a 25% reduction of complications related to heart disease.2 Furthermore, quitting smoking before heart disease develops reduces a person's risk of developing heart disease by 50% after 1 year and to that of a nonsmoker after 15 years.2
Exercising and adhering to a healthy diet are important treatments and preventive measures for heart disease. Participating in aerobic activity at least once per week reduces the risk of death, and increased activity results in further risk reduction. A diet high in fruits, nuts, vegetables, fish, dairy, and whole grains also can help prevent and reduce progression of heart disease. Focus should be placed on reduction of excess sugar, sodium, and trans-fat, as each has been associated with heart disease. Changes to exercise regimens and dietary habits can help maintain a healthy weight, with evidence suggesting that a reduction of BMI to <30 kg/m2 reduces one's risk of developing CAD by 50%.2
Although behavior and lifestyle changes play an important role in the prevention and reduction of heart disease, medications are also important for treatment. In certain populations with elevated atherosclerotic cardiovascular disease scores, medications (such as statins, which reduce cholesterol) reduce the risk of developing heart disease.2 Other medications, such as aspirin (taken daily), are associated with a decreased risk of MI in those diagnosed with CAD.2 Medications that treat comorbid medical illness (such as hypertension and diabetes) are crucial to the treatment and prevention of heart disease. Clinicians who deliver psychiatric care should monitor adherence to these medications and review the safety of these medications with regard to their direct and indirect effects on psychiatric illness.
How Should Psychiatrists Approach the Care of Patients With Heart Disease?
Psychiatric care of patients with heart disease should focus on the affective, behavioral, and cognitive components and interventions (Table 1).
The ABCs of Diagnosis and Treatment of Psychiatric Conditions in Heart Disease
Affective Considerations in the Care of Patients with Heart Disease
One approach to care for people with heart disease revolves around the diagnosis and treatment of both the affective consequences of heart disease and comorbid affective illness. In general, affective symptoms typically involve anxiety and depression. Affective symptoms are not necessarily reflective of isolated psychiatric illness but can be sequelae of acute medical illnesses, such as MI or stroke. For example, overwhelming anxiety, in association with chest pain, difficulty breathing, and shortness of breath may be life-threatening acute MI and not just a panic attack. Likewise, sudden changes in affective expression with motor deficits, changes in speech, and changes in alertness could suggest a stroke. Thus, during the evaluation of affective symptoms, careful attention should be paid to associated symptoms, including (but not limited to) chest pain, palpitations, shortness of breath, changes in sensory or motor function, syncope, changes in speech, periods of poor attention, or disorientation. Thus, the routine psychiatric care of patients with heart disease should include a comprehensive review of systems, basic vital signs (including heart rate, pulse oximetry, and blood pressure), and a routine physical examination (with specific attention paid to the pulmonary, cardiovascular, and neurologic systems).
Once underlying acute medical processes are ruled out or addressed, psychiatric care of affective symptom domains focuses largely on either treatment of underlying primary psychiatric illnesses or psychiatric symptoms associated with chronic medical illness.
Anxiety disorders. The diagnosis and treatment of anxiety disorders is important for the overall quality of life in patients with heart disease. Because many symptoms of heart disease (such as palpitations and shortness of breath) mimic and cause anxiety, symptoms of anxiety disorders can increase in frequency and amplitude as a result of heart disease. Anxiety is frequently reported in those with heart disease, with up to 28% of patients with CHF experiencing anxiety and up to 13% meeting criteria for anxiety disorder.5 Anxiety disorders associated with heart disease include generalized anxiety disorder, panic disorder, posttraumatic stress disorder (PTSD), or specific phobias.6,7 Hospitalizations, stays in the intensive care unit (ICU), acute cardiac events, and automatic implantable cardioverter defibrillator (AICD) firing increase anxiety. Moreover, several studies have shown a link among PTSD, MI, and post-AICD discharges.8,9
Although anxiety disorders are closely associated with heart disease, it is not clear what impact comorbid illness or untreated anxiety has on the morbidity or mortality associated with heart disease. Poor outcomes in those with untreated anxiety disorders are likely related to physiologic mechanisms (such as increased catecholamine release, increased corticosteroid release, autonomic dysfunction), inflammation, and behavioral patterns associated with anxiety disorders.10 Despite uncertainty related to the link between morbidity and mortality, treatment of anxiety remains crucial to the quality of life of patients with heart disease.
Depression in patients with heart failure. Growing evidence supports a close link between heart disease and depressive disorders. Rates of depression are increased in those with heart disease, as are rates of suicide,11,12 and depression is an independent risk factor for the development of heart disease.13 A variety of mechanisms (including increased inflammation, platelet activation, and endothelial dysfunction) have been proposed that might explain the link between depression and heart disease. Behavioral consequences of depression also contribute to poor adherence with rehabilitation programs and to decreased medication adherence.
Treatment of major depressive disorder should focus on both safety and efficacy. Selective serotonin reuptake inhibitors have been effective in the treatment of depression, and for the most part they are well tolerated and safe. Before initiating treatment for depression, clinicians should review the effects of medications on the QTc interval, blood pressure, and coagulation profile.
Behavioral Considerations for Patients with Heart Disease
Psychiatric care of patients with heart disease should focus on the evaluation and treatment of a variety of health behaviors related to heart disease. Many health behaviors and their consequences can lead to development of, and worsening of, CHF.2 Psychiatrists, given their specialized understanding and treatment of human behavior, are uniquely positioned to address certain unhealthy behaviors.
Smoking is a behavior that can be targeted for treatment. In addition to the use of nicotine-replacement therapies and medications for cravings, several other approaches for smoking cessation exist. The first is engaging the patient in the practice of recording his or her smoking habits, and taking careful note of environments, situations, and mood states. Clinicians can then work with patients to identify specific smoking cues or triggers. In addition to tracking daily smoking and triggers, cognitive-behavioral therapy often uses techniques of bolstering social support, emotional regulation, stress management, and coping with cravings. Mind-body approaches (including mindfulness techniques, meditation, body scans, and mindful exercising) to smoking cessation can help patients quit. These techniques can help patients identify somatic cues and triggers as well as redirect urges.
Diet and exercise are also potential behavioral targets that can improve cardiovascular health. In addition to participation in cardiac rehabilitation after a cardiac event, a regular exercise routine is critical to preventing heart disease. The American Heart Association (AHA) recommends doing at least 30 minutes of moderate-intensity aerobic activity at least 5 days per week or 25 minutes of vigorous aerobic activity at least 3 days per week.14 Patients should exercise for as long as they are safely able to. Psychiatrists can use several tools and approaches with patients, such as reviewing exercise journals and identifying potential barriers, use of motivational interviewing, or using the five-step cycle for coaching patients to adopt healthy habits.
Cognitive Considerations to the Care of Patients with Heart Disease
In addition to affective and behavioral considerations in patients with heart disease, cognitive components should be considered. Having heart disease can have a direct effect on a person's cognitive process, which can affect the thought process and decision-making, and result in unhealthy behaviors. Patients with heart disease are predisposed to strokes, which can directly influence cognitive functions, specifically executive function, motivation, and health behaviors.15 Patients with heart disease are also more susceptible to delirium, which is associated with poorer outcomes, longer ICU stays, and overall increased mortality.16
Psychiatric clinicians can play a key role in identifying cognitive deficits in patients. A variety of screening tools (such as the Montreal Cognitive Assessment or the Mini-Mental State Examination) may be used with patients to identify cognitive deficits as a result of vascular dementia or delirium. Using screens such as these, clinicians can better identify specific deficits in cognitive domains that affect health behaviors, such as medication adherence.
After identifying cognitive deficits, clinicians can help patients to achieve their goals despite deficits. For example, for patients with limited ability to plan and organize (as a result of vascular disease in the brain), the implementation of comprehensive home supports (such as home physical therapy and occupational therapy), a visiting nurse to assist with medications, or assistance in arranging transportation can aid patients who would otherwise be unable to plan this for themselves.