Supervised echocardiography in internal medicine. An integrated model in a community hospital.

Background: The management of patients admitted to an internal medicine ward frequently requires echocardiography, which may often be delayed because of overburdened specialist cardiologist services. The availability of appropriate echocardiography may be improved if internists first perform autonomous echocardiography on their cardiac patients. Our 5-year experience with such a model shows how it can exploit the complementary role of internists and cardiologists. Methods: We analysed data collected prospectively over 5 years, including patient characteristics, indications for investigation, time of execution, echocardiographic findings, incidence of technical failures and incomplete reports, and need for expert consultation, supervision, and review. Results: Out of 6035 admitted patients, 1943 (32%) had a primary cardiac discharge diagnosis and 1158 (19%) underwent transthoracic echocardiography (54% male, mean age 70.2+/-10.3 years). Heart failure, atrial fibrillation/flutter, and chest pain were the most frequent indications (19%, 14%, and 12% of cases, respectively). Technical failure occurred in 31 cases (2.7%) and incomplete information was provided in 127 cases (11%). Valvular and coronary heart diseases were the most frequent echocardiographic diagnoses (27% and 15%, respectively). Expert supervision, consultation, or review was required in 21 of the examinations (1.8%). Conclusion: Internists with training in echocardiography and adequate access to expert consultation can provide timely and clinically profitable echocardiographic information for the majority of their cardiac patients. The improved selection of their referrals allows cardiologists more time to devote themselves to detecting expertise-demanding pathology using special echocardiographic procedures. This integrated model can be applied in various clinical settings.

Variations of serum potassium level and risk of hyperkalemia in inpatients receiving low-molecular-weight heparin.

OBJECTIVES: To observe the variations of serum potassium level in patients receiving low-molecular weight heparin, assess the consequent risk of hyperkalemia and evaluate the clinical contributory factors. METHODS: A prospective study was performed on consecutive inpatients treated with low-molecular-weight heparin as indicated by the attending physicians. The changes of serum potassium level observed within 5-8 days were tested by univariate and multivariate analysis according to demographic and clinical variables and concomitant pharmacological therapy. RESULTS: Four hundred and sixteen patients (mean age 73 years; 64% female) were enrolled in the study over 15 months. After receiving nadroparin or enoxaparin (mean daily dosage: 76.3 anti-factor Xa unit/kg) for a median 6-day period, their mean (+/-SD) serum potassium level increased from 4.2+/-0.5 mmol/l to 4.5+/-0.5 mmol/l ( P<0.0001). This change was significantly correlated with baseline potassium, interval between potassium samplings, history of hypertension or renal insufficiency, and marginally with aldosterone antagonist treatment. Hyperkalemia, defined as potassium exceeding 5.5 mmol/l, developed in ten patients (2.4%) and the highest value observed was 7.6 mmol/l; by multivariate logistic-regression analysis, history of diabetes was the only significant independent predictor (odds ratio 6.5; 95% C.I.=1.7-24.8). CONCLUSION: Short-term treatment with low-molecular-weight heparin induces a significant increase in serum potassium level but the related incidence of relevant hyperkalemia is low. However, given the high absolute number of patients currently exposed to the risk in many clinical settings and the limitation of risk prediction, clinicians should prevent this life-threatening complication by a high index of suspicion and, accordingly, a quite routine monitoring of serum potassium.

Heart rate during myocardial infarction: relationship with one-year global mortality in men and women.

BACKGROUND: Elevated heart rate (HR) has been found to be related to an increased death rate in patients with acute myocardial infarction (AMI), but sex differences and optimal timing for HR measurement have not been sufficiently investigated. OBJECTIVES: To verify the predictive value of HR for one-year mortality in a cohort of subjects hospitalized for AMI, with men and women considered separately. PATIENTS AND METHODS: HR was measured in 424 patients (303 men and 121 women) with constant sinus HR, on the first, third and seventh days after hospital admission for AMI. Clinical and laboratory data were obtained on the same days. All patients were followed up for one year. RESULTS: Among the men, the one-year mortality rate was 5% for the subjects with a seven-day HR of less than 80 beats/min, and the one-year mortality rate was 39% for patients with a seven- day HR of 80 beats/min or more (P<0.0001). Among the women, the differences in mortality related to HR were not significant. In a multivariate Cox regression analysis, the relative risks of mortality in men who had an HR of 80 beats/min or more were 3.1 (CI=1.4 to 7.0, P=0.003) on the first day, 4.1 (CI=1.8 to 9.8, P=0.001) on the third day and 8.6 (CI=2.9 to 27.0, P<0.0001) on the seventh day. In the 203 men in whom echocardiographic left ventricular ejection fraction was measured, an interactive effect of high HR with depressed ejection fraction on mortality was found. Beta-blocking therapy influenced HR during AMI but did not influence the HR-mortality association. CONCLUSIONS: The results of the present prospective study show that HR measured during the first week after admission for AMI is an important predictor of mortality in men. The predictive power of HR increased from the first to the seventh day after AMI.

Heparin-induced life-threatening hyperkalemia.

Hyperkalemia may occur in many clinical settings and lead to serious events. Heparin-induced hyperkalemia is presumably less well recognized than other untoward effects of heparin treatment and more frequent than commonly perceived. To draw attention to this clinically relevant occurrence, we report 2 cases of life-threatening bradyarrhythmia associated with heparin prescription. Heparin-induced hyperkalemia is mediated by an enzymatic block in the synthesis of aldosterone; however, in most cases severe hyperkalemia occurs in the presence of additional factors influencing potassium homeostasis. Patients treated with heparin should be stratified and adequately monitored according to the outlined risk profile.