The macrolide group of antibiotics can cause QT prolongation, and endanger the patient with life threatening arrythmias. QT prolongation caused by Azythromycin, a relatively new macrolide, is extremely rare, and was not reported in clinical trials. Our hypothesis is that patients hospitalized with severe community acquired pneumonia, usually with multiple comorbid conditions will have a higher rate of QT prolongation, compared to the clinical trials published

Patients hospitalized with community aquired pneumonia will have their corrected QT measured daily during antibiotic therapy. Concomittant medications and electrolyte abnormalities that cause prolonged QT will be recorded

Inclusion Criteria:

• Severe community acquired pneumonia
• treated with azithromycin
• age over 18 years

Exclusion Criteria:

• Azithromycin initiated before hospitalization
• technically undecipherable ECG
• Permanent pacemaker

Patients hospitalized with severe community aquired pneumonia treated with azithromycin