Sudden dizziness or lightheadedness can derail your day in an instant, whether you are relaxing or pushing your physical limits. Even music icon Lionel Richie experienced this firsthand when he had to ask for a chair onstage during a performance at The Muny in St. Louis. The 77-year-old legend checked into the intensive care unit for comprehensive cardiac monitoring, giving millions of fans a brief scare. Fortunately, after a few days of thorough testing, People reports that he received a clean bill of health, was discharged and went home feeling great.

Moments like these (often referred to as presyncope) usually depend on how effectively your heart maintains steady blood flow to your brain. Your cardiovascular system acts as a constant supply pump, and any temporary drop in cerebral blood flow can leave you feeling disoriented, lightheaded or on the verge of fainting. These quick dips in circulation are typically triggered by sudden fluctuations in blood pressure, heart rhythm irregularities or a narrowed heart valve.

When unexpected dizziness strikes, particularly in older adults or active athletes engaged in demanding activities, a proper medical evaluation is essential. Hospital monitoring and diagnostic testing allow physicians to quickly detect and address underlying issues, such as dangerous arrhythmias, reduced blood flow to the heart muscle or structural heart conditions. Taking a beat to get checked out ensures that a scary dizzy spell remains a manageable bump in the road rather than a major health crisis.

Why was Lionel Richie in the ICU?

Lionel Richie’s hospitalization to intensive care was a very deliberate and controlled clinical action after several incidences of dizziness and physical exhaustion during his 2026 tour. The famed singer abruptly ended his show in St. Paul, Minnesota, two months earlier, after about 55 minutes, telling believers he was feeling lightheaded and joking that he was finally getting a chance to take an impromptu break while sitting down. While the initial cause of the event was thought to be minor dehydration and summer fatigue, the symptoms recurred in St. Louis, prompting a high-acuity evaluation.

When extended real-time hemodynamic monitoring is necessary, the standard practice is to admit the older person with recurrent dizziness to the intensive care unit. The ICU offers research-grade continuous cardiac telemetry, in which each beat, each change in rhythm and each fluctuation in blood pressure are monitored in real time by automated systems and critical care nurses. The high surveillance environment enables the cardiologist to exclude transient cardiac arrhythmias, acute coronary syndrome, severe electrolyte disorders or orthostatic vascular collapses, which are not adequately monitored on a standard hospital floor.

What is a cardiac workup?

Cardiologists rarely rely on a single tool to diagnose unexplained presyncope or suspected cardiovascular symptoms in the hospital. Rather, they use a comprehensive diagnostic workup of the heart, including continuous electrocardiography, comprehensive cardiac biomarker panels, transthoracic echocardiography and ambulatory rhythm monitoring.

The central component of this assessment begins with a 12-lead electrocardiogram (ECG) and continuous telemetry monitoring to assess the heart’s electrical conduction system, explains the Cleveland Clinic. This is combined with transthoracic echocardiography, a non-invasive ultrasound scan that produces real-time moving images of the heart’s interior chambers, muscular walls and fragile valves.

When used in combination with specialized laboratory blood tests measuring cardiac enzyme levels, this suite of tests provides a complete picture of the heart’s mechanical and electrical activity.

How it works

The different components of a hospital cardiac workup assess different physiological mechanisms and can help identify a patient’s specific source of symptoms. The ECG works by attaching sticky patches to the skin on the chest, arms and legs. According to the NIH, these sensitive sensors detect the tiny electrical currents that arise every time the cardiac muscle depolarizes and repolarizes, and convert them into recognizable waves, including the P wave, QRS complex and T wave. Telemetry systems can be used continuously in the ICU, and if they detect pauses, additional beats or dangerous changes in a patient’s rhythm, they alert immediately.

Dr. Justus Rabach, MD, explains to Blavity Health, “An echocardiogram uses high-frequency sound waves emitted by a hand-held ultrasound transducer that is pressed against the chest wall. These acoustic waves reflect off the muscular walls, the pericardial sac and the heart valves, and the ultrasound machine measures the time they take to return and converts the measurements into detailed cross-sectional images. In this test, a cardiologist can determine the percentage of blood pumped out of the main pumping chamber during each contraction (left ventricular ejection fraction, or LVEF) and check whether any heart valves are obstructed or don’t open completely.”

Along with imaging and electrical tracings, medical teams take a series of blood samples at hourly intervals to determine the levels of the blood marker known as high-sensitivity cardiac troponin (hsTnT). Troponins are structural (inside the myocardial cells) proteins that are only detectable in the blood when myocardial cells become damaged or deprived of oxygen, notes MedlinePlus. When troponin levels are completely undetectable across multiple tests, a physician is certain that there is no acute myocardial infarction or active heart muscle damage.

What can a cardiac workup detect?

The multidisciplinary cardiac workup is quite powerful and can reveal a vast array of functional, electrical and structural cardiovascular diseases that can lead to a sudden drop in blood pressure and dizziness.

The most important benefit of continuous rhythm testing is that it can detect intermittent cardiac arrhythmias that occur periodically and randomly. These include bradyarrhythmias, the heart is beating dangerously slowly as a result of sinus node dysfunction or heart block, and tachyarrhythmias, the heart is beating dangerously fast, for example, atrial fibrillation, atrial flutter, and ventricular tachycardia. If the heart rate is too fast or too slow, cardiac output drops, and within seconds, oxygenated blood is not delivered to the brain.

In addition, echocardiography can detect structural heart disease, such as aortic valve stenosis, which is a narrowing of the main outflow valve that occurs naturally with age and can cause blood to flow less freely into the aorta during exercise. It can also detect hypertrophic cardiomyopathy, congestive heart failure, localized wall motion abnormalities, and pericardial effusion (accumulation of fluid in a protective sac surrounding the heart). Severe electrolyte abnormalities, such as hypokalemia or hypomagnesemia, are detected with serial laboratory panels and can affect the cardiac conduction system.

Limitations

Modern cardiovascular diagnostics have advanced capabilities, but each test has definite, clinically significant limitations that must be interpreted judiciously. A 12-lead resting ECG only records the heart’s electrical activity for about 10 seconds. If an arrhythmia or transient conduction block is not actually occurring at that very 10-second moment, it will not appear on the tracing. It will give a false sense of reassurance, a PMC publication notes.

In the same way, an ECG can reveal a lot about the heart’s structure and mechanics, but it cannot directly image the coronary arteries to see the tiny buildup of plaque. In addition, patient body habitus, chest wall structure, and underlying lung disease (such as chronic emphysema) can sometimes impair ultrasound image quality.

Resting tests also do not reflect cardiovascular function under high metabolic stress, extreme dehydration or performance states influenced by adrenaline, frequently necessitating later outpatient ambulatory monitoring or formal exercise stress testing post-stabilization.

Risks and safety considerations

During a precautionary cardiac hospitalization, the first-line tests are non-invasive and have negligible physiological risk to the patient. Resting electrocardiograms, continuous bedside telemetry and transthoracic echocardiograms do not use ionizing radiation or chemical dyes and do not involve any physical discomfort other than minor skin irritation from adhesive sensor pads.

If, however, diagnostic results indicate further secondary testing is warranted, safety becomes more of an issue. Under controlled medical supervision, a patient might experience a temporary episode of chest tightness and flushing, shortness of breath or a temporary arrhythmia if a patient needs an exercise (or pharmacological) stress test, and the heart rate is increased through physical exertion on a treadmill or by administering a drug such as regadenoson.

If the doctor sees signs of serious myocardial ischemia and suggests an invasive coronary angiogram, the patient lies on a table, and a thin catheter is inserted through the radial or femoral artery under fluoroscopy. Invasive catheterization is standard, safe, but has minor risks of small amounts of bleeding in the area, allergic reactions to the iodine dye used to make the images visible, stress on the kidneys, or damage to the artery wall (rarely).

Alternatives

Patients who still have episodes of lightheadedness despite normal inpatient telemetry and echocardiography are next referred for extended ambulatory monitoring and special stress testing.

Doctors prescribe wearable external cardiac monitors, like Holter monitors, which record every heartbeat for 24 to 48 hours, or wireless patch monitors, which continuously monitor cardiac rhythms for up to two weeks while the person goes about their normal life. A short outpatient procedure may be performed to insert a tiny device (about the size of a paperclip) just under the skin of the chest wall, which can continuously monitor electrical activity for up to three years, even during rare events.

Cardiologists often use a non-invasive test called Coronary Computed Tomography Angiography (CCTA) to assess blockages in the coronary arteries that supply the heart muscle. The CCTA scan is an advanced type of CT scan that uses intravenous contrast to produce high-resolution, three-dimensional maps of the coronary arteries, measure calcium scores and identify soft atherosclerotic plaques before they completely block the arteries. In certain situations where the cause of fainting remains unknown, a tilt table test may also be ordered to evaluate the body’s regulation of blood pressure and heart rate as it moves from supine to upright.

“A low score indicates mild plaque; therefore, lifestyle changes such as improving diet, exercising and lowering cholesterol will help,” says board-certified cardiologist Dr. Robert Segal, founder of Manhattan Cardiology. “A high score indicates that you should work with your doctor to reduce your risk, maybe with statins.”

Bottom line

The precautionary hospitalization and recovery of Lionel Richie underscore the importance of evaluating dizziness and fatigue without a clear explanation on a structured cardiac test. Together with continuous rhythm telemetry, echocardiographic imaging and high-sensitivity blood biomarkers, critical care teams can detect or rule out potentially life-threatening arrhythmias, valvular abnormalities and cardiac muscle damage. By taking lightheadedness seriously as a possible red flag for a vascular disorder and seeking appropriate medical attention, people can help protect the long-term health of their hearts and remain physically active.

Frequently Asked Questions

What are the most common cardiac tests performed by doctors?

The most common frontline cardiac tests performed by clinicians include the 12-lead electrocardiogram (ECG), continuous telemetry rhythm monitoring, transthoracic echocardiography and blood tests measuring high-sensitivity troponin levels.

What test shows blockages in your heart?

An invasive coronary angiogram (cardiac catheterization) or a non-invasive Coronary Computed Tomography Angiography (CCTA) scan is the primary medical imaging test that directly visualizes and measures plaque blockages within the coronary arteries.

Citations

Avila D, Rubenstein J. Lionel Richie Is Back Home and ‘Doing Great’ Following 3-Day Hospitalization (Exclusive). People.com. Published September 2, 2026. https://people.com/lionel-richie-is-back-home-doing-great-following-hospitalization-exclusive-12077126

Cleveland Clinic. Electrocardiogram (EKG) | Cleveland Clinic. Cleveland Clinic. Published 2019. https://my.clevelandclinic.org/health/diagnostics/16953-electrocardiogram-ekg

Ashley EA, Niebauer J. Conquering the ECG. National Library of Medicine. Published 2004. https://www.ncbi.nlm.nih.gov/books/NBK2214/

MedlinePlus. Troponin Test: MedlinePlus Lab Test Information. medlineplus.gov. Published October 30, 2023. https://medlineplus.gov/lab-tests/troponin-test/

Rizzo C, Monitillo F, Iacoviello M. 12-lead electrocardiogram features of arrhythmic risk: A focus on early repolarization. World Journal of Cardiology. 2016;8(8):447. doi:10.4330/wjc.v8.i8.447