Dysrhythmias III: Characteristics of Dysrhythmias

Sinus tachycardia occurs when the SA node fires at 100-180 beats per minute, maintaining a regular rhythm. The ECG shows normal P waves preceding each QRS complex with a normal PR interval. This condition arises from the sinus node firing more rapidly due to stimuli such as fever, exercise, or stress.

Premature atrial contractions (PACs) are early beats from an ectopic focus in the atria. The ECG shows early P waves that differ in shape from normal sinus P waves and may be hidden in the preceding T wave. The rhythm is generally irregular, with heart rate varying based on PAC frequency.

Atrial flutter involves a single reentrant circuit in the atria, causing rapid, regular atrial contractions at 200-350 beats per minute. This reentrant activity produces the characteristic sawtooth pattern, known as flutter waves, on the ECG. The ventricular rate depends on the degree of AV block.

Atrial fibrillation results from chaotic electrical activity in the atria, with an atrial rate reaching 350-600 beats per minute. This disorganized activity prevents organized atrial contractions, eliminating distinct P waves and replacing them with fibrillatory waves. The result is an irregular ventricular response and inefficient blood circulation.

Ventricular tachycardia originates from the ventricles and displays wide, distorted QRS complexes at 150-250 beats per minute. In contrast, paroxysmal supraventricular tachycardia shows narrow QRS complexes at the same rate range, with abnormal electrical pathways above the ventricles. VT can be monomorphic or polymorphic in rhythm pattern.

Ventricular fibrillation is a life-threatening condition where chaotic electrical signals cause the ventricles to quiver ineffectively. The ECG displays irregular, disorganized waveforms of varying amplitude and shape. This prevents coordinated contractions, stopping blood circulation and requiring immediate medical intervention through dysrhythmias vii nursing management of dysrhythmias protocols.

Atrial flutter maintains a regular atrial rate of 200-350 beats per minute due to a single reentrant circuit. Atrial fibrillation produces a faster, chaotic atrial rate of 350-600 beats per minute from disorganized electrical activity. Despite higher atrial rates, atrial fibrillation results in irregular ventricular response, while atrial flutter typically maintains regular ventricular rhythm.