Sudden cardiac death refers to an unexpected loss of heart function, breathing and consciousness. It occurs when the heart suddenly stops pumping blood effectively due to problems with the heart’s electrical system. This leads to a sudden loss of blood flow to vital organs such as the brain, lungs and kidneys. Some of the common symptoms that may precede sudden cardiac death include:
Chest Pain
One of the most common early warning signs of sudden cardiac arrest is chest pain or discomfort. This may feel like tightness, heaviness, squeezing or pain in the center or left side of the chest. It can range from mild to severely painful. Chest pain results from reduced blood supply to the heart muscle, indicating a problem with the coronary arteries. If untreated, it can progress to a full blown heart attack and cardiac arrest.
Shortness of Breath
Difficulty in breathing or shortness of breath (dyspnea) can also precede sudden cardiac death. It occurs when the heart is unable to pump enough blood to meet the body’s demands. Shortness of breath may begin with exertion but later progress to occurring at rest. It may be accompanied by wheezing, rapid breathing, sweating or bluish discoloration of the skin due to inadequate oxygenation.
Dizziness or Lightheadedness
Some people may feel lightheaded, dizzy or feel like they may faint before experiencing sudden cardiac death. This results from a transient drop in blood pressure and reduced blood flow to the brain when the heart’s pumping action is impaired. The sensation of dizziness may be exacerbated by exertion or standing up suddenly. Severe dizziness may cause the person to faint or collapse.
Fatigue
Excessive and persistent fatigue or tiring easily is another warning sign of impending sudden cardiac arrest. Heart failure leads to reduced oxygenation and nutrient supply which can profoundly affect energy levels. Fatigue may not always be relieved by rest. It may be accompanied by muscle weakness, especially when climbing stairs or exercising.
Palpitations
Palpitations refer to an uncomfortable awareness of one’s heart beat. It may feel like the heart is racing, pounding, fluttering or throbbing in the chest. Palpitations result from arrhythmias or abnormal electrical signals in the heart’s upper chambers (atria). This may trigger ventricular tachycardia and other dangerous heart rhythms associated with sudden cardiac death.
Loss of Consciousness
Some individuals may experience a sudden, unexplained loss of consciousness in the time leading up to sudden cardiac death. Fainting (syncope) results from critically low blood flow to the brain. It may be preceded by lightheadedness or dizziness and usually resolves quickly when lying down. Recurrent, unexplained syncope requires prompt medical attention.
Nausea and Vomiting
Nausea and vomiting may precede sudden cardiac arrest in some cases. Activation of the vagus nerve due to arrhythmias slows down digestion and causes nausea. Vomiting may also result from inadequate blood flow to the gastrointestinal system and stimulate the vomiting reflex. The nausea and vomiting associated with heart disease may be accompanied by abdominal swelling.
Anxiety and Sweating
Some individuals experience a sudden onset of anxiety, apprehension or a sense of doom prior to cardiac arrest. This may be accompanied by a cold sweat, clammy skin and paleness. It reflects activation of the sympathetic nervous system due to abnormal heart rhythms and deteriorating cardiovascular function. The anxiety and nervous system response exacerbates the arrhythmia.
Cough and Wheezing
The accumulation of fluid in the lungs (pulmonary edema) due to heart failure can stimulate coughing. This is the result of fluid irritating the bronchial airways. The cough is often worse at night and when lying down. It may be accompanied by audible wheezing or crackling noises and frothy or bloody sputum.
Confusion
Altered mental status and confusion can occur prior to sudden cardiac arrest due to inadequate blood flow to the brain. Confusion may be mild or more severe, progressing to an inability to think or speak clearly. Disorientation, memory lapses and delirium may be present. The onset may be rapid in acute cardiac crises.
Conclusion
In summary, sudden cardiac death may have subtle early warning signs and symptoms hours or days before the actual event. These include chest pain, shortness of breath, dizziness, fatigue and palpitations. Loss of consciousness, nausea, anxiety and cough may also precede sudden cardiac arrest. Many of these symptoms reflect underlying heart disease progression. Recognizing the warning signs allows early intervention which can prevent sudden death in some cases.