When a patient complains of feeling dizzy or light-headed, don’t overlook neurological or other causes, but first think about a cardiac cause.
When a patient complains of feeling dizzy or light-headed, think about a cardiac cause first, but don’t overlook neurological or other causes, says an emergency medicine specialist.
“Always think about a cardiac cause first. It’s the go-to diagnosis, and it should be because it’s the most common cause of light-headedness,” Nilesh Patel, DO, Emergency Medicine Student Clerkship Director at St. Joseph’s Regional Medical Center in Paterson, NJ, told a crowded auditorium at the American Academy of Emergency Medicine’s 20th Annual Scientific Assembly in New York.
Primary care physicians often overlook neurological and other diagnoses. “Take a good history and physical,” Dr Patel says. “Is the dizziness intermittent? This is almost never a stroke, and usually is benign positional vertigo. If the dizziness is persistent, to rule out a stroke, look for context, for example, abnormal eye movement.” If a patient has any neurological signs, then think stroke until proved otherwise. “You may need to do a neurologic workup and get a CT or MRI scan,” he says.
Dr Patel notes that a patient in near-syncope should have bloodwork done and an ECG. “If the patient has positive troponin, think cardiac. But other diagnoses can also have increased troponin,” he says.
Syncope and near-syncope are similar conditions, the major difference being patients with near-syncope do not lose consciousness. Dizziness and light-headedness also are similar. Patients with dizziness feel disequilibrium and vertigo. Those who are light-headed feel faint. Dr Patel notes, “Patient reports of symptoms are unreliable, and so are our perceptions of the symptoms.”
Dr Patel’s “Must Know List” of signs includes the following:
• Cardiac: bradydysrhythmias, tachydysrhythmias, valvular disease, acute coronary syndrome, long QT wave, Brugada syndrome, Wolff–Parkinson–White syndrome, and idiopathic hypertrophic subaortic stenosis.
• Neurological: subarachnoid hemorrhage, stroke, and transient ischemic attack.
• Other: thoracic aortic dissection, pulmonary embolism, abdominal aortic aneurysm, bleeding, anaphylaxis, electrolyte abnormalities, metabolic disturbances, and carbon monoxide (CO) poisoning.
Patients with pulmonary embolism may express symptoms of near-syncope. “When pulmonary embolism patients present with dyspnea, we tend to make the right diagnosis,” Dr Patel says. “For patients with dizziness and syncope, we tend to miss pulmonary embolism. These patients tend to be sicker and often have poor right ventricular function.”
Obstructions can be dynamic. Clots may change position, fragment, and move distally, which may lead to transient loss of consciousness.
Dizziness also could result from a stroke, even in younger patients who may have no apparent weakness, hemiparesis, or aphasia. These patients are often given a misdiagnosis of migraine headache plus neurological symptoms or gastroenteritis. “Make sure the symptoms fit the diagnosis,” Dr Patel says.
Posterior circulation strokes, which constitute 15% to 20% of cerebrovascular accidents, are underestimated. Symptoms include headache, vertigo, light-headedness, and nausea. The most common sign is having difficulty in sitting up in bed.
CO poisoning also may lead to near-syncope. “One-third of cases of CO poisoning go undetected,” Dr Patel says. “Home CO detectors have not reduced the incidence of CO poisoning, and we don’t know why. The pathophysiology of CO poisoning is complicated. Vital signs are not helpful.”
During the winter, maintain a high index of suspicion of CO poisoning, Dr Patel says. “Ask whether anyone else at home, including pets, is sick. That’s a sign of potential exposure to CO.”