Cardiac Testing Results

Automaticity

The ability to produce an electrical impulse

Excitability

The ability to respond to an electrical stimulus

Conductivity

The ability to transport an electrical stimulus

Contractility

The ability to contract when stimulated

Sinus bradycardia

a heart rate below 60 bpm with normal P waves, QRS complexes, and consistent R-R intervals. This can be seen in athletes or during sleep but may indicate vagal stimulation or medication effects.

Sinus tachycardia

a heart rate above 100 bpm, typically caused by exercise, fever, pain, or stress. The rhythm remains regular, with normal P waves and QRS complexes.

Sinus arrhythmia

a normal variation where the R-R interval slightly fluctuates, often increasing with inhalation and decreasing with exhalation. This is more common in young, healthy individuals.

Atrial dysrhythmias

occur when electrical impulses originate in the atria rather than the SA node.

Premature atrial contractions (PACs)

early beats originating in the atria, often with an abnormal P wave but normal QRS complex. They may be triggered by caffeine, stress, or electrolyte imbalances.

Atrial flutter

a rapid atrial rate (250-350 bpm) with a characteristic "sawtooth" flutter wave pattern instead of distinct P waves. The ventricular rate may be regular or irregular depending on AV conduction.

Atrial fibrillation (AFib)

chaotic,uncoordinated atrial activity with no visibleP waves and an irregularly irregular ventricular response. AFib increases the risk of stroke and requires medical intervention.

Junctional rhythms

originate from the atrioventricular (AV) junction, often due to SA node failure.

Junctional escape rhythm

A slow, regular rhythm (40-60 bpm) with absent or inverted P waves, as impulses travel retrograde toward the atria

Accelerated junctional rhythm

A faster rate (60-100 bpm) with the same absent/inverted P-wave characteristics, often due to enhanced AV nodal activity

Junctional tachycardia

"A rapid junctional rhythm (over 100 bpm) that may be caused by

digitalis toxicity or other cardiac conditions"

Ventricular dysrhythmias

"are often more serious because

they can significantly impact cardiac output."

Premature ventricular contractions (PVCs)

are early, wide, and bizarre-looking QRS complexes with no preceding P wave. PVCs may occur in isolation or in patterns (e.g., bigeminy, trigeminy).

Ventricular tachycardia (VTach)

"a series of consecutive PVCs leading to a sustained ventricular rate of 100+ bpm. This is a potentially life-threatening rhythm requiring

immediate attention."

Ventricular fibrillation (VFib)

is chaotic, unorganized electrical activity in the ventricles, leading to no effective cardiac output. A medical emergency requiring immediate defibrillation.

Asystole

"a condition where there is a complete absence

of electrical activity in the heart, often referred to as a

"flatline.""

(STEMI)

ST-Elevation Myocardial Infarction

Ischemia

"Reduced blood flow to the

heart muscle, often seen as ST depression or

T wave inversion"

Infarction (Myocardial Infarction - MI)

"Permanent heart muscle damage due to prolonged

lack of oxygen"

Dilation

Enlargement of a heart chamber due to volume overload

Hypertrophy

Thickening of the heart muscle due to increased workload

Pulseless Electrical Activity

condition where electrical activity is presenton an EKG, but the heart is not pumping blood effectively