Racing Heart: What Causes Rapid Ventricular Response (RVR)?

[jobaidurr611]

Rapid Ventricular Response (RVR) is a clinical state where the heart's lower chambers, the ventricles, beat excessively fast, typically exceeding 100 beats per minute, in response to abnormally fast electrical signals originating from the atria (upper chambers). RVR is not a primary arrhythmia itself but rather a complication of certain supraventricular (above the ventricles) arrhythmias. Understanding what causes RVR is critical, as sustained rapid rates can lead to symptoms like palpitations, dizziness, shortness of breath, and, over time, even heart failure.

Atrial Fibrillation with RVR: The Most Common Scenario
The overwhelming most common cause of Rapid Ventricular luxembourg telegram database Response is Atrial Fibrillation (AFib) with RVR. Atrial fibrillation is an arrhythmia where the atria beat chaotically and irregularly, often at rates exceeding 350-600 beats per minute. The atrioventricular (AV) node, which normally acts as a gatekeeper, becomes overwhelmed by these rapid atrial impulses. While the AV node blocks some impulses to protect the ventricles, in AFib with RVR, it conducts too many of these impulses, allowing a rapid and irregular barrage to reach the ventricles, causing them to beat quickly and erratically. The individual's physiology, the state of the AV node, and sympathetic tone all influence how many impulses are conducted.

Atrial Flutter and Other Supraventricular Tachycardias
Beyond atrial fibrillation, atrial flutter is another common cause of RVR. In atrial flutter, the atria beat rapidly but in a more organized, typically regular pattern (e.g., 250-350 beats per minute). The AV node may conduct these impulses at a fixed ratio (e.g., 2:1 or 3:1 conduction), leading to a rapid but often regular ventricular rhythm. For instance, a 2:1 block in atrial flutter at 300 bpm would result in an RVR of 150 bpm. Other, less common supraventricular tachycardias (SVTs), such as AV nodal re-entrant tachycardia (AVNRT) or AV re-entrant tachycardia (AVRT), can also cause RVR, although these often manifest as a rapid, regular ventricular rate, unlike the typically irregular rate of AFib with RVR.

Factors Influencing AV Nodal Conduction
Several factors can influence the AV node's conduction properties, thereby contributing to RVR. Increased sympathetic nervous system activity (e.g., due to stress, exercise, fever, infection, or hyperthyroidism) can enhance AV nodal conduction, allowing more rapid impulses to reach the ventricles. Conversely, medications that depress AV nodal function (e.g., beta-blockers, calcium channel blockers) are often used to control RVR. Underlying conditions such as heart failure, electrolyte imbalances (e.g., hypokalemia), and certain drug toxicities can also make the heart more susceptible to developing and sustaining RVR by altering the heart's electrical environment. Prompt management of RVR often involves medications to slow AV nodal conduction or, in severe cases, electrical cardioversion to restore normal rhythm.

Note: As "what causes rapid ventricular response" and "what causes rvr" are identical, I've provided one comprehensive article to cover both.