Syncope, commonly known as fainting, involves a partial or complete lapse in consciousness, disrupting a person's awareness of themselves and their environment. When this loss of consciousness is brief and recovery happens spontaneously, it is often termed as fainting or blackout in layman's terms. Syncope is a reason for approximately one out of every 30 emergency room visits and is pronounced "sin-ko-pea."Syncope occurs due to a temporary decrease in blood flow, resulting in insufficient oxygen reaching the brain. This can trigger an episode of "blacking out" or losing consciousness. Such a temporary disruption in blood supply to the brain may result from heart-related issues or non-cardiac conditions.Non-cardiac causes are often more prevalent and include:- **Postural changes**: A sudden drop in blood pressure from shifting positions, such as standing up quickly after lying or sitting.- **Dehydration**: This reduces blood volume, affecting circulation.- **Blood pressure medications**: These can sometimes lead to syncope.- **Nerve issues in the legs**: Common in older adults, especially those with diabetes or Parkinson’s disease, where the blood pools in the legs instead of reaching the brain.- **Transient ischemic attacks (TIA)**: Also called "mini-strokes," these can temporarily impair brain function.- **Situational triggers**: Fainting might occur during activities such as blood drawing, urination (micturition syncope), defecation, swallowing (swallow syncope), or coughing. These can activate a reflex in the autonomic nervous system (the parasympathetic system), which slows the heart rate and dilates blood vessels in the legs, potentially causing nausea, sweating, or weakness before fainting.Cardiac causes of syncope include:- **Abnormal heart rhythms**: The heart may beat too fast or too slow.- **Heart valve issues**: Problems with the aortic or pulmonic valves.- **Pulmonary artery conditions**: Such as blockages.- **Aortic dissection**: Tears in the aorta.- **Cardiomyopathy**: Widespread heart muscle disease.Diagnosing the exact cause of syncope often involves a thorough medical history. For example, dizziness upon standing in older individuals may indicate postural hypotension, while fainting after urination or coughing suggests situational syncope. Cardiac-related syncope, like that caused by aortic stenosis, often occurs during physical exertion, while weakness in specific body areas during a fainting spell may suggest a stroke.Evaluations include measuring blood pressure and heart rate in different positions (lying, sitting, standing), checking for unequal blood pressure between arms (indicating possible aortic dissection), and using a stethoscope to listen for any signs of valve abnormalities. Neurological tests assess sensation, reflexes, and motor functions, while an EKG checks for heart rhythm irregularities. Additional tests might include echocardiograms, heart event monitors, and electrophysiologic studies.If heart issues are ruled out, tilt-table testing can help identify non-cardiac causes of syncope. This test involves securing the patient on a table that tilts to various angles while monitoring blood pressure, pulse, and symptoms.For many non-cardiac syncope cases, like postural hypotension, vasovagal reactions, and situational syncope, no treatment is necessary. Consciousness often returns simply by sitting or lying down. Patients are advised to avoid known triggers, refrain from straining during elimination, sit while coughing, and lie down during procedures like blood drawing. For older adults, reviewing medications and slowly transitioning from lying to standing can help accommodate slower nerve adjustments in the legs.
