A patient develops sudden palpitation with HR 150/ min, regular. What could be the cause-
**Core Concept**
The patient's symptoms suggest a sudden increase in heart rate, which could be due to various factors, including autonomic nervous system dysfunction, cardiac arrhythmias, or other systemic causes. The regular rhythm of the palpitations indicates a possible supraventricular origin.
**Why the Correct Answer is Right**
The correct answer is likely related to a sudden increase in sympathetic tone, which can cause an increase in heart rate. This can be due to various factors, including stress, anxiety, or certain medications. The body's "fight or flight" response is mediated by the sympathetic nervous system, which increases heart rate, contractility, and vascular tone. In this case, the patient's heart rate is 150/min, which is significantly elevated. This suggests a possible abnormality in the autonomic nervous system's regulation of heart rate.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely incorrect because it does not provide a plausible explanation for the sudden increase in heart rate. A heart attack or myocardial infarction would more likely cause chest pain, shortness of breath, or other symptoms.
* **Option B:** This option is incorrect because a high fever would more likely cause symptoms such as chills, sweating, or confusion, rather than a sudden increase in heart rate.
* **Option C:** This option is incorrect because a pulmonary embolism would more likely cause symptoms such as sudden onset of dyspnea, chest pain, or coughing up blood.
**Clinical Pearl / High-Yield Fact**
In patients with palpitations, it's essential to assess the rhythm and rate of the heartbeat, as well as the patient's overall clinical condition. A regular rhythm with a high heart rate may indicate a supraventricular tachycardia, while an irregular rhythm may suggest a more complex arrhythmia.
**Correct Answer:** D