Final answer:
The treatment for Polymorphic VT with a normal QT interval typically involves beta-blockers. Potassium channel blockers like amiodarone and procainamide affect ventricular repolarization. Calcium channel blockers may also be used but are not the first line of treatment for this condition.
Step-by-step explanation:
The treatment for Polymorphic Ventricular Tachycardia (VT) with a normal baseline QT interval may vary based on the underlying cause, but common treatments include the use of beta-blockers, which are known to be effective in managing arrhythmias and certain types of VT. Medications like amiodarone and procainamide, which are potassium channel blockers, impact the action potential of the heart by affecting the ventricular repolarization. They impede the movement of K+ through voltage-gated K+ channels, prolonging the repolarization phase and thus potentially stabilizing the cardiac rhythm. However, abnormal levels of electrolytes such as magnesium and potassium can also cause arrhythmias, and supplementation might be required if the arrhythmia is due to deficiencies of these ions.
Calcium channel blockers can slow the heart rate by blocking calcium ions that affect contractility and heart rate, but they are generally not the first line of treatment for polymorphic VT unless there is a specific indication. Therefore, the correct response for treating polymorphic VT with a normal baseline QT interval is likely to be beta-blockers (option c).