Final answer:
A tachyarrhythmia is defined as any heart rhythm other than sinus tachycardia with a rate above 100 bpm, indicating a rapid and irregular heartbeat. Diagnosis and treatment depend on the underlying cause and may involve various medical interventions.
Step-by-step explanation:
A tachyarrhythmia is defined as "any rhythm other than sinus tachycardia with a rate greater than 100 beats per minute (bpm)." Tachycardia, when not in the context of exercise or stress, is not considered normal in resting patients. It may be detected in cases such as pregnancy, extreme stress, or due to various medical conditions including fever, anemia, hypoxia, and hyperthyroidism. In tachyarrhythmias, the rapid heart rate is caused by disorganized electrical impulses, often originating from areas outside the sinus node, leading to an irregular rhythm.
While a resting heart rate above 100 bpm is generally considered as tachycardia, arrhythmias can include a broad range of rhythms where the rate may be too fast, too slow, or irregular. Common types of tachyarrhythmias include atrial fibrillation, atrial flutter, and ventricular tachycardia. Symptoms, when present, may include dizziness, shortness of breath, lightheadedness, chest pain, or fainting. Proper diagnosis is essential for treatment, which may involve medications, cardioverter defibrillators, ablation, or surgery, depending on the underlying cause.