LIFE THREATENING HYPERKALEMIA WITH ECG CHANGES AND RHYTHM DISTURBANCE AS AN ADVERSE EFFECT OF POTASSIUM SPARING DRUGS USED IN TREATMENT OF CARDIOVASCULAR DISEASES IN ELDERLY PATIENTS

Introduction:  Due to growing prescription of potassium sparing drugs in cardiology (angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, direct renin inhibitors, potassium sparing diuretics, spironolactone) the risk of hyperkalemia is growing  in clinical practice.  75% of hyperkalemia cases in institutionalized patients are  induced by potassium sparing pharmacotherapy. The mortality rate of patients with  hyperkalemia >7.0 mmol/L  can achieve 67% if it is not corrected immediately. Iatrogenic hyperkalemia interferring ion homeostasis endagers especially old people with comorbid conditions, polypharmacy and low  function reserves.  As the course of hyperkalemia is often oligosymptomatic until severe, the arrhythmia may be the first symptom of impaired potassium homeostasis.
Aim and method: to assess the risk of hyperkalemia in old persons treated by potassium sparing drugs,  document severe ECG changes and arrhythmias in life threatening hyperkalemia > 9.0mmol/L and  suggest further treatments.
Results: In life threatening hyperkalemia ( ≥ 9.0mmol/L) in presented cases we found severe rhythm disturbances and deformations of QRS complexes (atrial asystole, III degree atrioventricular block, disturbance of intraventricular conduction, bizzare wide QRS complexes). In individual case reports the ECG changes will be presented  and other complications of hyperkalemia as failure of permanent atrial and ventricular cardiac pacing are discussed.
Conclusion:  Severe hyperkalemia is a life – threatening condition  requiring emergent therapy. It is necessary to emphasize the prevention of hyperkalemia, screening of hyperkalemia in  patients on potassium sparing drug therapy, especially   at the beginning  or  when  changing  the treatment  or in the case of coincidence of  another acute illness.