Lidocaine-induced conduction disturbance in patients with systemic hyperkalemia

Severe hyperkalemia presenting with wide-complex tachycardia in a puppy with acute kidney injury secondary to leptospirosis

OBJECTIVE

To describe a case of hyperkalemia coinciding with wide-complex tachycardia (WCT) in a dog with acute kidney injury secondary to leptospirosis infection.

CASE SUMMARY

An 11-week-old Golden Retriever-Standard Poodle cross puppy was referred for acute kidney injury and hepatopathy. WCT coinciding with marked hyperkalemia was identified on presentation. Tachycardia persisted until resolution of hyperkalemia.

NEW OR UNIQUE INFORMATION PROVIDED

To our knowledge, this is the first report of severe hyperkalemia presenting with WCT in a dog. Hyperkalemia should be considered a differential for WCT in dogs.

The hyperkalemic Brugada sign

BACKGROUND

A few case reports have indicated that hyperkalemia can induce a Brugada pattern in the electrocardiogram. The specific clinical and electrocardiographic features of the hyperkalemic Brugada sign, however, have not been previously described.

METHODS

A case series was collected from hospitalized hyperkalemic patients with a type I Brugada pattern in the electrocardiogram, and a literature review was performed. Electrocardiograms were examined for rhythm and morphology, and clinical characteristics were analyzed.

RESULTS

Nine new cases with the hyperkalemic Brugada sign were identified with an additional 15 cases found in the literature. Of the 9 cases, 8 were male patients, and all were critically ill; 5 of the 9 died within 48 hours. The mean (+/-SD) serum potassium level was 7.8 +/- 0.5 mEq/L. The mean QRS width was 144 +/- 31 milliseconds, and all had abnormal QRS axis. In 6 cases, there was a wide complex rhythm without visible P waves. The clinical and electrocardiographic characteristics of 15 cases found in the literature were remarkably similar to those in our series.

CONCLUSIONS

The hyperkalemic Brugada pattern differs in substantial ways from the electrocardiogram of patients with the genetic Brugada syndrome. Many patients have wide complex rhythms without visible P waves, marked QRS widening, and an abnormal QRS axis. Most patients are male, and many are critically ill. Prompt recognition of this clinical and electrocardiographic entity may expedite the initiation of appropriate treatment for hyperkalemia.

Wide-complex tachycardia: beyond the traditional differential diagnosis of ventricular tachycardia vs supraventricular tachycardia with aberrant conduction

Wide-complex tachycardia (WCT) is defined as a rhythm disturbance with a rate greater than 100 beats/min and a QRS complex duration of 0.12 seconds or more in the adult patient; in the pediatric patient, both rate and QRS complex width are age related. In evaluating this type of tachycardia, there are 2 broad categories usually discussed in the medical literature: ventricular and supraventricular with aberrant intraventricular conduction. There are several other important causes of a WCT encountered in clinical practice, which are less often discussed; these tachycardias often require specific therapies differing from the standard approach to WCT. These tachycardias are diverse; as such, the pathophysiology behind each form of WCT includes toxic, metabolic, and conduction system dysfunction mechanisms.

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