Anthracycline Cardiotoxicity – Clinical Types

Anthracycline cardiotoxicity – clinical types

Anthracyclines are very effective in the chemotherapy of cancer. But their Achilles heel is cardiotoxicity. Three clinical types of anthracycline cardiotoxicity have been described [1]:

1. Acute – usually occurring within two weeks of initiation of treatment, with the first dose or first course of chemotherapy.
2. Early onset chronic – usually occurring within a year. This is the most frequent type and presents with features suggesting dilated cardiomyopathy.
3. Late onset chronic – occurs years or even decades later.

Acute cardiotoxicity though rare, is potentially lethal and may include pericarditis and arrhythmias [2] additional manifestations over and above left ventricular dysfunction. Twenty four hour Holter monitoring showed that only 3% had arrhythmia within the first hour after infusion and 24% in subsequent 23 hours. But no acute or long term adverse consequences related to the arrhythmia were noted in that study. Mechanism of acute cardiotoxicity may be inflammatory and different from that of chronic toxicities.

Cardiotoxicity has been classified into type I and II. Type I is caused by death of cardiomyocyte by necrosis or apoptosis and not reversible. Long term toxicity belongs to this type. Type II is due to cardiomyocyte dysfunction and may be reversible.

References

1. Volkova M, Russell R 3rd. Anthracycline cardiotoxicity: prevalence, pathogenesis and treatment. Curr Cardiol Rev. 2011 Nov;7(4):214-20.
2. Steinberg JS, Cohen AJ, Wasserman AG, Cohen P, Ross AM. Acute arrhythmogenicity of doxorubicin administration. Cancer. 1987 Sep 15;60(6):1213-8.