A concussion is a mild traumatic brain injury (TBI) resulting from a blow to the head or a jolt to the body that temporarily alters normal brain function. This injury causes chemical and functional changes within the brain, leading to symptoms like headache, dizziness, and confusion. A heart attack, or myocardial infarction, occurs when blood flow to a section of the heart muscle is severely reduced or blocked, usually by a clot. While a direct link between a concussion and a traditional heart attack involving blocked arteries is not established, a physiological connection exists between brain trauma and cardiac distress. Central nervous system disruption following a concussion can trigger events that place severe stress on the cardiovascular system, which can mimic a heart attack or lead to other serious heart conditions.
Brain Injury and Nervous System Overload
A concussion initiates a disturbance in the body’s control system, particularly the Autonomic Nervous System (ANS), which regulates involuntary functions like heart rate, blood pressure, and breathing. The ANS operates through two branches: the sympathetic nervous system (“fight or flight”) and the parasympathetic nervous system (“rest and digest”). Normally, these two systems maintain a careful balance to keep the body’s internal environment stable.
Following a traumatic brain injury, this regulatory balance is thrown into disarray, often resulting in sympathetic overdrive. The brain responds to trauma by flooding the body with a surge of stress hormones, known collectively as catecholamines, which include epinephrine and norepinephrine. This chemical surge acts directly on the heart muscle and blood vessels.
The excessive presence of catecholamines forces the heart to work harder, dramatically increasing both heart rate and blood pressure. This hormonal surge constricts blood vessels and can cause microvascular spasm, placing intense strain on the coronary arteries and the heart muscle itself. This sustained chemical stress can directly damage heart tissue. Dysregulation is often measured by a decrease in heart rate variability (HRV), indicating a loss of the heart’s flexible response.
Cardiac Conditions Triggered by Concussion
The sympathetic nervous system’s reaction to a concussion can directly trigger specific cardiac outcomes that are distinct from a typical heart attack caused by plaque rupture. One severe condition resulting from catecholamine overload is Takotsubo Cardiomyopathy, often called “stress cardiomyopathy.” This condition causes a temporary weakening and ballooning of the left ventricle, the heart’s main pumping chamber, which physically resembles an ancient Japanese octopus pot.
Takotsubo Cardiomyopathy mimics the symptoms of a traditional heart attack, including chest pain and shortness of breath, but occurs without significant coronary artery blockage. The condition is a direct result of the toxic effect of high stress hormone levels on the heart muscle cells. Though often reversible, Takotsubo Cardiomyopathy can lead to acute heart failure and requires immediate medical intervention.
Arrhythmias and Myocardial Markers
Beyond this stress-induced muscle damage, the autonomic imbalance can also provoke dangerous irregularities in the heart’s rhythm, known as arrhythmias. These can range from a rapid heart rate (tachycardia) to a dangerously slow rate (bradycardia). A concussion can also cause a prolongation of the heart’s electrical recovery period, known as QT prolongation, which significantly increases the risk of sudden, life-threatening ventricular arrhythmias. When the heart muscle is stressed by catecholamines, it can release enzymes into the bloodstream, such as troponin, which are myocardial injury markers. An elevation of these markers indicates damage to the heart muscle, even if a classic heart attack has not occurred.
Recognizing Emergency Heart Symptoms
While general symptoms like headache, nausea, and dizziness are common after a concussion, it is important to distinguish these from signs of acute cardiac distress, which demand immediate emergency care. The symptoms of a heart problem following a head injury are often the same as those of a traditional heart attack. Recognizing these red flags quickly can make a difference in patient outcome.
Seek emergency medical attention immediately if you experience new or worsening chest pain or discomfort that does not go away with rest. This chest sensation may feel like pressure, squeezing, fullness, or an ache. Pay close attention if the pain radiates from the chest into the arm, shoulder, back, neck, jaw, or upper stomach.
Severe shortness of breath that occurs at rest or with minimal activity is a serious sign of cardiac distress. Other emergency symptoms include sudden, severe lightheadedness, a fainting spell, or a feeling of a rapid, irregular, or fluttering heart rate. Any combination of these symptoms following a head injury suggests a possible acute cardiac event and requires an immediate emergency room visit for a full cardiovascular assessment.