When a storm's maximum sustained winds reach 74 mph, it is called a hurricane. The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 rating, or category, based on a hurricane's maximum sustained winds. The higher the category, the greater the hurricane's potential for property damage. Hurricanes originate in the Atlantic basin, which includes the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico, the eastern North Pacific Ocean, and, less frequently, the central North Pacific Ocean.
paroxysmal supraventricular tachycardia (PSVT) a narrow QRS tachycardia that begins and ends abruptly; it may be terminated with a vagal maneuver. It has two common mechanisms, atrioventricular nodal reentry and circus movement that uses the atrioventricular node anterogradely and an accessory pathway retrogradely.
Paroxysmal supraventricular tachycardia (paroxysmal SVT) is an episodic condition with an abrupt onset and termination. (See Etiology and Presentation.) SVT in general is any tachyarrhythmia that requires atrial and/or atrioventricular (AV) nodal tissue for its initiation and maintenance.