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.
The signal is conducted through the atria (the upper heart chambers) and stimulates the atria to contract. Paroxysmal supraventricular tachycardia (PSVT) can be initiated in the SA node; in the atria or the atrial conduction pathways; or in the AV node. It occurs most often in young people and infants. Risks include smoking, caffeine, alcohol use, and illicit drug use. PSVT can occur with digitalis toxicity.