What does an increased PR interval mean?

A prolonged PR interval represents a delay in the time it takes for the signal to move across the atria at the top of the heart, which receive blood flowing in from the veins, into the ventricles at the bottom of the heart, which pump blood out into the arteries.

Does digoxin cause PVCs?

Other common dysrhythmias associated with digoxin toxicity include: Frequent PVCs (the most common abnormality), including ventricular bigeminy and trigeminy. Sinus bradycardia. Slow Atrial Fibrillation.

Which ECG finding shows digoxin toxicity?

The ECG shows a few important features of digitalis intoxication: sinus node depression, AV junctional rhythm, and ventricular bigeminal rhythm arising in the fascicles of left bundle branch system. Narrow negative P waves suggest atrial activation starting centrally near the low interatrial septum.

What are signs of digoxin toxicity?

Symptoms

• Confusion.
• Irregular pulse.
• Loss of appetite.
• Nausea, vomiting, diarrhea.
• Fast heartbeat.
• Vision changes (unusual), including blind spots, blurred vision, changes in how colors look, or seeing spots.

How long is the QT interval for digoxin?

Shortened QT interval. Mild PR interval prolongation of up to 240 ms (due to increased vagal tone). Prominent U waves. Peaking of the terminal portion of the T waves. J point depression (usually in leads with tall R waves).

How often do digoxin injections need to be increased?

The recommended starting maintenance dose in adult patients with normal renal function is given in Table 2. Doses may be increased every 2 weeks according to clinical response, serum drug levels and toxicity. Table 3 provides the recommended (once daily) maintenance dose for adult patients according to lean body weight and renal function.

What are the effects of digoxin on the AV node?

Shortening of the atrial and ventricular refractory periods — producing a short QT interval with secondary repolarisation abnormalities affecting the ST segments, T waves and U waves. Increased vagal effects at the AV node — causing a prolonged PR interval.

How much digoxin is needed for an electrocardiogram?

Effect of Digoxin. At therapeutic levels, digoxin can cause effects on the electrocardiogram, which must be differentiated from digoxin toxicity (see below). The optimal serum concentration of digoxin is 0.5 ng/ml to 1.0 ng/ml. Given the low therapeutic range, your serum levels should be monitored periodically 6.