The atrial heart rate is rapid (250-350 bpm), but ventricular rate is often slower. ECG rhythm will appear more regular thank atrial fibrillar. P wave and PR interval are not observable, but saw-toothed flutter waves are present. The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm P wave features should appear normal and the PR interval is normal (0.12-0.20 sec). The QRS complex will typically be wide (>0.12 sec).

The P wave will be normal while the PR interval is prolonged (>0.20 sec). The QRS complex will typically be normal (0.06-0.10 sec). A first degree av block occurs when electrical impulses moving through the atrioventricular (AV) node are delayed (but not blocked). The adjective first degree indicates slowed conduction without missed beats.

The ECG rhythm will appear regular with a very slow heart rate(20-40 bpm). The P wave will be absent and the PR interval is not measurable. The QRS complex will typically be wide (>0.10 sec) and a bizarre appearance.

The ECG rhythm will appear regular. Heart rate that is slow (40-60 bpm). The P wave will be present before, during (hidden) or after QRS, if visible it is inverted. The PR interval is not measurable. The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm will appear regular with a fast heart rate (100-180 bpm). The P wave can appear before, during (hidden) or after QRS, if visible it is inverted. Observe that the PR interval is absent or short. The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm will appear irregular with a fast heart rate (> 100 bpm). The P wave features often change shape and size from beat to beat with at least three differing forms. Observe that the PR interval is variable. The QRS complex will typically be normal (0.06-0.10 sec). In addition, the T wave can be distorted.

The ECG rhythm will appear regular with a normal (60-100 bpm) heart rate. The P wave appears normal and precedes each QRS. Observe that the PR interval is normal (0.12-0.20 sec). The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm will appear irregular with heart rate that is slow or normal. Observe that the pacemaker spikes are not followed by p waves or QRS complexes.

The ECG rhythm will appear irregular and pacemaker spikes do not appear.

The ECG rhythm will appear regular with heart rate that is normal. The P wave and PR interval will both appear normal. The QRS complex is also normal. Pacemaker spikes will precede the P wave.

The ECG rhythm will appear irregular with heart rate that is usually normal but depends on underlying rhythm. The P wave will appear premature, positive and a shape that is abnormal. Observe that the PR interval is normal or longer. The QRS complex will typically be 0.10 sec or less.

The ECG rhythm will appear regular with premature beats with heart rate that is the underlying rate. The P wave is present before, during (hidden) or after QRS. If the P wave is visible, it is inverted. Observe that the PR interval is absent or short. The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm will appear irregular with heart rate that is the underlying rate. The P wave features absent. Observe that the PR interval is not measurable. The QRS complex will typically be wide (> 0.10 sec) with a bizarre appearance.

The ECG rhythm will appear irregular with an absent P wave and the PR interval is not measurable. The QRS complex will typically be wide (> 0.10 sec) with a bizarre appearance. The PVC appears on every second beat.

The ECG rhythm will appear irregular. The P wave is absent and the PR interval is not measurable. The QRS complex will typically be wide (> 0.10 sec) and bizarre in appearance. The PVC appears every fourth beat.

The ECG rhythm will appear irregular. The P wave is absent and the PR interval is not measurable. The QRS complex will typically be wide (> 0.10 sec) with a bizarre appearance. The PVC appears every third beat.

The ECG rhythm will appear irregular but with progressively longer pr interval lengthening. The P wave is normal. Observe that the PR interval becomes progressively longer until a QRS complex is missed, then cycle repeats. The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm will appear regular (atrial) and irregular (ventricular) with heart rate that is characterized by atrial rate that is usually faster than ventricular rate (usually slow). The P wave has a normal form, but more P waves than QRS complexes. The PR interval is normal or prolonged. The QRS complex will typically be normal or wide.

The ECG rhythm will appear irregular when SA block occurs with a normal or slow heart rate. The P wave will be normal and the PR interval will be normal (0.12-0.20 sec). The QRS complex will typically be normal (0.06-0.10 sec). The pause time is an integer multiple of the p-p interval.

The ECG rhythm will appear irregular due to a pause with heart rate that is normal to slow. The P wave is normal. The PR interval is normal (0.12-0.20 sec). The QRS complex will typically be normal (0.06-0.10 sec). Pause time is not an integer multiple of the p-p interval.

The ECG rhythm will appear irregular, varying with respiration with heart rate that is normal (60-100 bpm) and rate may increase during inspiration. The P wave is normal and the PR interval is also normal (0.12-0.20 sec). The QRS complex will typically be normal (0.06-0.10 sec). Heart rate frequently increases with inspiration, decreasing with expiration.

The ECG rhythm will appear regular with a slow heart rate (under 60 bpm). The P wave and the PR interval are normal. The QRS complex will typically be normal (0.06-0.10 sec).

The ECG rhythm will appear regular with a fast heart rate (> 100 bpm). The P wave normal but may merge with T wave at very fast rates. Observe that the PR interval is>normal (0.12-0.20 sec). The QRS complex will typically be normal (0.06-0.10 sec). The QT interval shortens with increasing heart rate.

The ECG rhythm will appear regular and heart rate that will be fast (150-250 bpm). The P wave will be merged with T wave. The PR interval is normal (0.12 sec) but can be difficult to measure. The QRS complex will typically be normal (.10 sec).

The ECG rhythm will appear regular, but atrial and ventricular rhythms are independent. Heart rate is characterized by atrial rate usually normal but faster than the ventricular rate. The P wave will have normal shape and size but may appear within QRS complexes. The PR interval is absent: the atria and ventricles beat independently. The QRS complex will typically be normal, but wide if junctional escape focus.

The ECG rhythm will appear highly irregular with an unmeasurable heart rate. The P wave is absent, the PR interval is not measurable and no QRS complex. The ECG tracings is a wavy line.

The ECG rhythm will appear regular with heart rate that is fast (100-250 bpm). The P wave is absent and the PR interval is not measurable. The QRS complex will typically be wide (>0.10 sec) with a bizarre appearance.

The ECG rhythm will appear regular with a fast (100-250 bpm) heart rate. The P wave is absent and the PR interval is not measurable. The QRS complex will typically be wide (>0.10 sec) and bizarre looking.

The ECG rhythm will appear regular or irregular with heart rate that is fast (100-300 bpm). The P wave is absent and the PR interval is not measurable. The QRS complex will typically be normal or wide (>0.10 sec) with a bizarre shape.

The ECG rhythm will appear irregular with heart rate that is fast (200-250 bpm). The P wave is absent and the PR interval is not measurable. The QRS complex will typically be wide (>0.10 sec). Its shape is characterized by a gradual change in the ECG amplitude and a twisting of the QRS complexes around a line.

The ECG rhythm will appear may be irregular with a normal heart rate. The P wave can be observed changing shape and size from beat to beat (at least three different forms). The PR interval is variable in duration. The QRS complex will typically be normal (0.06-0.10 sec) and the T wave normal. If heart rate exceeds 100 bpm, then rhythm may be multifocal atrial tachycardia (MAT).

The ECG rhythm will appear regular unless atrial fibrillation present. Heart rate is normal (60-100 bpm). The P wave is normal. Observe that the PR interval is can be short (less than 0.12 sec). The QRS complex will typically be wide (over 0.12 sec). A delta wave (positive or negative) distorts the early part of the QRS complex.