Prolonged QTc intervals on the electrocardiograms of hospitalized malnourished adults

We investigated whether hospitalized malnourished adults would have longer QTc intervals on their electrocardiograms (ECGs) than non-malnourished adults. Seventy-five consecutive adults hospitalized in the Internal Medicine wards of our teaching hospital were prospectively studied. Main diagnoses, anthropometry, including body mass index (kg/m(2)), ECGs, and simultaneous serum levels of sodium, potassium, magnesium, phosphorus, and calcium were recorded. All QT intervals on ECGs were measured in a semiautomatic image analysis system; and QTc intervals were determined with the Bazett formula. Protein-energy malnutrition (PEM) was diagnosed with body mass index below 18.5 kg/m(2). There was no statistical difference between malnourished (n = 30) and non-malnourished (n = 45) with regard to age (40.7 +/- 18.9 y versus 41.4 +/- 16.2 y), male predominance (66.7% versus 80%), or associated diagnoses. Compared with non-malnourished, malnourished patients had higher percentages of positive C-reactive protein (66.7 versus 23.8%), lower serum levels of albumin (2.51 +/- 0.89 g/dL versus 3.41 +/- 0.74 g/dL) and potassium (3.64 +/- 0.65 mEq/L versus 4.12 +/- 0.65 mEq/L), and increased QTc lengths on ECGs (0.423 +/- 0.033 ms versus 0.396 +/- 0.031 ms). Malnourished adults hospitalized in general clinical wards are more likely to have longer QTc intervals on their ECGs, a phenomenon possibly linked to malnutrition and associated electrolyte disturbances.