Clinical Pearls & Morning Reports
Anxiety and cardiac illnesses have a complex relationship owing to substantial symptom overlap. Read the latest Case Records of the Massachusetts General Hospital here.
Q: Describe an endocrine disorder that is associated with anxiety and with atrial fibrillation.
A: Excessive production of thyroid hormone, which is often associated with the autoimmune disorder Graves’ disease, can cause anxiety and panic, muscle weakness, palpitations, and weight loss. Hyperthyroidism most frequently occurs in women older than 60 years of age and is associated with atrial fibrillation. Thyroid dysfunction is a common medical cause of psychiatric symptoms that is considered when other supporting physical symptoms are present.
Q: At what age does panic disorder typically present?
A: Panic disorder is an anxiety disorder that is characterized by recurrent, unexpected panic attacks. The onset of panic disorder usually occurs during the third decade of life. Symptoms of a panic attack — palpitations, diaphoresis, dyspnea, nausea, and chest discomfort — are virtually identical to symptoms of acute coronary syndromes or arrhythmias. Patients with anxiety have increased perception of internal bodily sensations, or “interoceptive awareness,” which means that they are more likely to scan for and negatively interpret visceral cues, such as subtle changes in heartbeat, breathing, and other factors.
A: Psychiatric symptoms have been linked to the development and persistence of atrial fibrillation. Specifically, anxiety after cardiac surgery and panic disorder have been linked to the development of atrial fibrillation. In cross-sectional studies, depressive symptoms were associated with an increased likelihood of atrial fibrillation, and patients with atrial fibrillation had higher levels of trait (persistent) anxiety than patients with hypertension. Furthermore, 8.4% of patients with atrial fibrillation met criteria for major depressive disorder at any given time — a prevalence that is slightly higher than the yearly prevalence of major depressive disorder in the general population. Patients with anxiety and depression may have increased severity of atrial fibrillation symptoms, which is perhaps caused by increased interoceptive awareness.
A: All antipsychotic agents have been associated with prolongation of the QT interval, but this effect is thought to be most severe with the use of low-potency phenothiazines, such as thioridazine. In contrast, aripiprazole, an atypical antipsychotic that has the unique property of acting as a partial dopamine agonist, has been shown to cause the least severe QT prolongation. Among antidepressant agents, tricyclic antidepressants are most classically associated with QT prolongation because of their blockade of sodium channels. Selective serotonin-reuptake inhibitor (SSRIs) have largely been considered to be safe in this regard and have been well studied in cardiac populations. The use of citalopram, the SSRI with the greatest potential for QT prolongation, is not recommended at doses of more than 40 mg daily or at doses of more than 20 mg daily in patients older than 60 years of age or with liver dysfunction.