Prolonged QTc intervals on the electrocardiograms of hospitalized malnourished adults

The implications of hyperoxia, type 1 diabetes and sex on cardiovascular physiology in mice

Oxygen supplementation, although a cornerstone of emergency and cardiovascular medicine, often results in hyperoxia, a condition characterized by excessive tissue oxygen which results in adverse cardiac remodeling and subsequent injurious effects to physiological function. Cardiac remodeling is further influenced by various risk factors, including pre-existing conditions and sex. Thus, the purpose of this experiment was to investigate cardiac remodeling in Type I Diabetic (Akita) mice subjected to hyperoxic treatment. Overall, we demonstrated that Akita mice experience distinct challenges from wild type (WT) mice. Specifically, Akita males at both normoxia and hyperoxia showed significant decreases in body and heart weights, prolonged PR, QRS, and QTc intervals, and reduced %EF and %FS at normoxia compared to WT controls. Moreover, Akita males largely resemble female mice (both WT and Akita) with regards to the parameters studied. Finally, statistical analysis revealed hyperoxia to have the greatest influence on cardiac pathophysiology, followed by sex, and finally genotype. Taken together, our data suggest that Type I diabetic patients may have distinct cardiac pathophysiology under hyperoxia compared to uncomplicated patients, with males being at high risk. These findings can be used to enhance provision of care in ICU patients with Type I diabetes as a comorbid condition.

Copper and magnesium deficiencies in patients with short bowel syndrome receiving parenteral nutrition or oral feeding

BACKGROUND

Patients with short bowel syndrome have significant fluid and electrolytes loss.

OBJECTIVE

Evaluate the mineral and electrolyte status in short bowel syndrome patients receiving intermittent parenteral nutrition or oral feeding.

METHODS

Twenty two adults with short bowel syndrome, of whom 11 were parenteral nutrition dependent (PN group), and the 11 remaining had been weaned off parenteral nutrition for at least 1 year and received all nutrients by oral feeding (OF group). The study also included 14 healthy volunteers paired by age and gender (control group). Food ingestion, anthropometry, serum or plasma levels of sodium, potassium, phosphorus, magnesium, calcium, zinc, iron and copper were evaluated. PN group subjects were evaluated before starting a new parenteral nutrition cycle.

RESULTS

The levels of sodium, potassium, phosphorus, calcium and zinc were similar between the groups. The magnesium value was lower in the PN group (1.0 ± 0.4 mEq /L) than other groups. Furthermore, this electrolyte was lower in the OF group (1.4 ± 0.3 mEq /L) when compared to the Control group (1.8 ± 0.1 mEq/L). Lower values of copper (69±24 vs 73±26 vs 109±16 µg/dL) were documented, respectively, for the PN and OF groups when compared to the control group.

CONCLUSION

Hypomagnesemia and hypocupremia are electrolyte disturbances commonly observed in short bowel syndrome. Patients with massive intestinal resection require monitoring and supplementation in order to prevent magnesium and copper deficiencies.

To Identify Myocardial Changes in Severely Malnourished Children: A Prospective Observational Study

AIM AND OBJECTIVE

The main purpose of this study is to identify the myocardial changes in severely malnourished children.

MATERIALS AND METHODS

This prospective, observational study, conducted for a period of 1 year, enrolled 200 children (120 males and 80 females) between 6 months and 5 years of age with severe protein-energy malnutrition, according to the criteria of the World Health Organization. The parents were duly informed, the study was explained and written consent was obtained. A random selection of cases was carried out, and they were further divided into five groups according to their age as follows: <1, 1-2, 2-3, 3-4, and 4-5 years. Electrocardiograms (ECGs) were taken at the time of admission for all the cases and the control group and were taken again after nutritional therapy either at the time of discharge or after a fortnight. The differences were then compared.

RESULTS

On admission, 32% of cases had flat P-wave, out of which 75% reverted to normal with therapy. Similarly, 84% of cases had increased corrected QT interval at the time of admission. ST segment was depressed only in 8% of cases. 88% of cases had altered (flat to depressed) T wave at the time of admission. With the help of nutritional supplementation, all these abnormalities were back to a normal level at the time of discharge.

CONCLUSION

Electrocardiographic changes may be of help in assessing the severity and prognosis of severe acute malnutrition. The reversibility of ECG changes with dietary treatment suggests that the cardiac changes are not permanent in nature and may not affect adult life if the malnutrition is corrected. The cardiac status as denoted by heart rate remained the same even after a fortnight, suggesting that prolonged therapy and assessment of cardiac status is warranted even after fortnight therapy.

Enteral nutrition for feeding severely underfed patients with anorexia nervosa

Severe undernutrition nearly always leads to marked changes in body spaces (e.g., alterations of intra-extracellular water) and in body masses and composition (e.g., overall and compartmental stores of phosphate, potassium, and magnesium). In patients with severe undernutrition it is almost always necessary to use oral nutrition support and/or artificial nutrition, besides ordinary food; enteral nutrition should be a preferred route of feeding if there is a functional accessible gastrointestinal tract. Refeeding of severely malnourished patients represents two very complex and conflicting tasks: (1) to avoid "refeeding syndrome" caused by a too fast correction of malnutrition; (2) to avoid "underfeeding" caused by a too cautious rate of refeeding. The aim of this paper is to discuss the modality of refeeding severely underfed patients and to present our experience with the use of enteral tube feeding for gradual correction of very severe undernutrition whilst avoiding refeeding syndrome, in 10 patients aged 22 ± 11.4 years and with mean initial body mass index (BMI) of 11.2 ± 0.7 kg/m(2). The mean BMI increased from 11.2 ± 0.7 kg/m(2) to 17.3 ± 1.6 kg/m(2) and the mean body weight from 27.9 ± 3.3 to 43.0 ± 5.7 kg after 90 days of intensive in-patient treatment (p < 0.0001). Caloric intake levels were established after measuring resting energy expenditure by indirect calorimetry, and nutritional support was performed with enteral feeding. Vitamins, phosphate, and potassium supplements were administered during refeeding. All patients achieved a significant modification of BMI; none developed refeeding syndrome. In conclusion, our findings show that, even in cases of extreme undernutrition, enteral feeding may be a well-tolerated way of feeding.

Serum 25-hydroxyvitamin D, calcium, phosphorus, and electrocardiographic QT interval duration: findings from NHANES III and ARIC

CONTEXT

Disturbances in 25-hydroxyvitamin D, calcium, and phosphorus concentrations have been associated with increased risks of total and cardiovascular mortality. It is possible that changes in electrocardiographic QT interval duration may mediate these effects, but the association of 25-hydroxyvitamin D, phosphorus, and calcium concentrations with QT interval duration has not been evaluated in general population samples.

OBJECTIVE

The objective of the study was to evaluate the association of 25-hydroxyvitamin D, phosphorus, and calcium concentrations with QT interval duration in two large samples of the U.S. general population.

DESIGN

This study included cross-sectional analyses the Third National Health and Nutrition Survey (NHANES III) and the Atherosclerosis Risk in Communities (ARIC) study.

SETTING

The study was conducted in the general community.

PATIENTS OR OTHER PARTICIPANTS

Patients included 7,312 men and women from NHANES III and 14,825 men and women from the ARIC study.

INTERVENTIONS

Serum 25-hydroxyvitamin D, total and ionized calcium, and inorganic phosphorus were measured in NHANES III, and serum total calcium and inorganic phosphorus were measured in ARIC.

MAIN OUTCOME MEASURE

QT interval duration was obtained from standard 12-lead electrocardiograms.

RESULTS

In NHANES III, the multivariate adjusted differences in average QT interval duration comparing the highest vs. the lowest quartiles of serum total calcium, ionized calcium, and phosphorus were -3.6 msec (-5.8 to -1.3; P for trend = 0.005), -5.4 msec (-7.4 to -3.5; P for trend <0.001), and 3.9 msec (2.0-5.9; P for trend <0.001), respectively. The corresponding differences in ARIC were -3.1 msec (-4.3 to -2.0; P for trend <0.001), -2.9 msec (-3.8 to -1.9; P for trend <0.001), and 2.3 msec (1.3-3.3; P for trend <0.001). No association was found between 25-hydroxyvitamin D concentrations and QT interval duration.

CONCLUSIONS

In two large samples of the general population, QT interval duration was inversely associated with the serum total and ionized calcium and positively associated with serum phosphorus.

Factors associated with a prolonged QT interval in liver cirrhosis patients

AIM

The aim of this study was to identify factors associated with prolonged QT interval in liver cirrhosis patients.

MATERIALS AND METHODS

Thirty-eight patients with liver cirrhosis were enrolled in this study. The maximal QT interval (QTmax), heart rate-corrected QT interval (QTc), QT interval in lead DII (QTII), and mean QT interval (QTm) were determined manually, using 12-lead electrocardiogram. Additional laboratory tests were also performed.

RESULTS

The following values were obtained: QTmax, 435 ± 43 milliseconds; QTc, 493 ± 46 milliseconds; QT interval in lead DII, 405 ± 46 milliseconds; and mean QT interval, 400 ± 40 milliseconds. Ten (6%) patients had a prolonged QTmax, and 27 (71%) had a prolonged QTc. The highest values were obtained for QTc and QTmax in patients with alcoholic cirrhosis and Child-Pugh class C, respectively. A moderate correlation was observed between QTmax and serum uric acid (URCA; r = 0.504), and multiple linear regression analysis revealed that URCA was significantly associated with QTc and heart rate.

CONCLUSIONS

Liver disease severity, alcoholic etiology, and URCA are associated with prolonged QT interval in patients with liver cirrhosis.

An Evaluation of P Wave Dispersion, QT, Corrected QT and Corrected QT Dispersion Intervals on the Electrocardiograms of Malnourished Adults

The aim of our study was to investigate P wave dispersion (Pwd), QT, corrected QT (QTc), QT dispersion (QTd) and corrected QT dispersion (QTcd) intervals in subjects with malnutrition diagnosed in the pre-anaesthetic assessment, compared to those without malnutrition.

A total of 76 adult patients were included. Main diagnoses, anthropometric measurement, body mass index, electrocardiogram and serum sodium, potassium, chloride, magnesium and calcium levels were recorded for all patients. Pwd, QT and QTd intervals were measured on all electrocardiogram records and QTc and QTcd intervals determined with the Bazett formula. Protein-energy malnutrition was diagnosed with the nutritional risk index.

No statistically significant difference was found between the age, gender and malignant cancer diagnosis rates between patients with malnutrition (group M) and those not suffering from malnutrition (group N) (P >0.05). Serum albumin, total protein, potassium, calcium, magnesium and chloride values of group M were found to be significantly lower than group N (P <0.05). In group M, Pwd, QT, QTc, QTd and QTcd intervals were significantly longer than in group N (P <0.001).

Patients diagnosed with malnutrition during pre-anaesthetic assessment had significantly longer Pwd, QTc and QTcd interval durations than the control group. We attribute such extended Pwd, QTc and QTcd durations in these patients to malnutrition and malnutrition-related electrolyte imbalance.

Intrauterine growth retardation is a risk factor for cisapride-induced QT prolongation in preterm infants

BACKGROUND

Cisapride is a possible cause of potentially life threatening QT prolongation.

AIMS

We investigated these cardiac side effects in premature infants, mainly in relation to fetal growth.

PATIENTS

Forty six preterms (mean birth weight 1.350 g, mean post conceptional age 31 weeks) were studied. Thirty-one of them were appropriate for gestational age (AGA) and 15 were small for gestational age (SGA). Cisapride was randomly administered at a 0.3 mg/kg or 0.6 mg/kg daily dose. Fifty preterms (15 SGA/35 AGA) not treated with Cisapride were used as control group.

METHODS

A pre-treatment ECG was performed and the QT-corrected (Bazzet's formula) intervals were compared with the in-treatment values (normal values < or =440 mseconds). In the control group two different ECG were performed with a timing similar to the treated group (mean interval 5 days).

RESULTS AND CONCLUSIONS

No patients showed clinical evidence of drug toxicity. In the small for gestational age group, both baseline QTc (mean 397; range 370-420 ms) and in-treatment QTc (mean 410 range 360-500 ms) were significantly higher than those found in the appropriate for gestational age group (mean 386, range 360-420 ms; mean 396, range 370-420 ms, respectively). This difference was found also in the first ECG of the control group. Moreover the mean QTc lengthening during treatment was significantly higher in small for gestational age group than in the appropriate for gestational age group. Three infants showed a rise in the QTc interval above the value of 440 ms and all were SGA (p = 0.03). No significant correlation was found between birth weight or gestational age and the change in QTc values during Cisapride treatment in the appropriate for gestational age group. Intrauterine growth retardation is a major risk factor for Cisapride-induced QT prolongation in preterm infants.

Prolongation of the QT interval in palliative care patients

Prolonged QT interval on the electrocardiogram (ECG) is associated with an increased risk of cardiac arrhythmia and sudden death. Many drugs used in palliative medicine increase the QT interval and several have had their licenses withdrawn or severely restricted. The relative importance of prolonged QT interval will increase for palliative medicine physicians when dealing with patients with longer prognoses and especially cardiac disease. Given these safety concerns, the aim of this study was to determine the prevalence of a prolonged QT interval in palliative care patients who were not in the terminal stage and were referred to a specialist service. Of 300 patients, 47 (16%) had prolonged QTc but only two had QT >500ms. The presence of coexistent cardiac disease or high levels of serum alkaline phosphatase appear to be the clinical features most robustly associated with a prolonged QTc. Although prolonged QTc is relatively common in patients referred to a specialist palliative care service, severely prolonged QT is rare.