Complete atrioventricular block associated with concomitant use of metoprolol and paroxetine

A 63-year-old woman, who had been treated with 20 mg of paroxetine and 0.5 mg of alprazolam daily for 1 year and with 50 mg of metoprolol daily for 15 days, presented to a facility elsewhere with presyncope and complete atrioventricular block. Three days after her initial presentation and cessation of metoprolol treatment, she was transferred to our clinic to be considered for permanent pacemaker implantation. Paroxetine treatment was discontinued on day 1 and atrioventricular block resolved on day 5, which was confirmed with a 24-hour Holter recording. No bradyarrhythmia was induced with similar doses of either metoprolol or paroxetine alone. At 2- and 3-year follow-up, the patient was still free of bradyarrhythmia documented with electrocardiography and 24-hour Holter recordings. To our knowledge, we report the first case of complete atrioventricular block associated with coadministration of paroxetine and metoprolol. Increasing physicians' awareness of drug-induced severe bradyarrhythmia might prevent unnecessary implantation of permanent pacemakers.

Effect of nebivolol and metoprolol treatments on serum asymmetric dimethylarginine levels in hypertensive patients with type 2 diabetes mellitus

OBJECTIVE

Elevated asymmetric dimethylarginine (ADMA) levels, an endogenous inhibitor of nitric oxide synthase, are an important cardiovascular risk factor. In patients with diabetes, increased ADMA levels have been reported, which may be associated with endothelial dysfunction. In this study, effect of nebivolol on serum ADMA levels in hypertensive patients with type 2 diabetes have been compared with metoprolol, an another beta-blocker.

METHODS

A total of 54 patients (27 female, 27 male; mean age: 53.0+/-8.7 years) with type 2 diabetes and hypertension were included in this randomized, open-label, prospective study. Patients were randomized to receive either nebivolol 5 mg/day (n=28) or metoprolol 100 mg/day (n=26) for 12 weeks. When the patients could not reach target blood pressure levels at the end of week 4, indapamide (2.5 mg/day) was added. Enzyme Linked Immunosorbent Assay was used for serum ADMA measurements.

RESULTS

Similar reductions in blood pressure values were observed in both groups (p>0.05). In nebivolol group, there were no significant changes in serum ADMA levels compared to baseline (0.6+/-0.2 micromol/l vs 0.6+/-0.1 micromol/l, p>0.05), whereas in metoprolol group a 35.6% increase in serum ADMA levels was observed (0.6+/-0.1 micromol/l vs 0.7+/-0.2 micromol/l, p<0.01).

CONCLUSION

We observed a significant increase in ADMA levels, a marker of endothelial dysfunction, during metoprolol treatment, whereas nebivolol had neutral effects on ADMA levels in patients with type 2 diabetes mellitus and hypertension.

Comparative clinical study of the efficacy and safety of a S-metoprolol ER tablet versus a racemate metoprolol ER tablet in patients with chronic stable angina

OBJECTIVE

To compare the efficacy and safety of a S-metoprolol extended release (ER) tablet (50 mg) versus a racemate metoprolol ER tablet (100 mg) in the management of angina.

METHODS

An open-label, prospective, comparative study in a clinical setting was conducted in Indian patients. Patients (n = 50 in each group) with a history of angina pectoris, with or without hypertension, were administered study medications in a sequential 1:1 manner once daily for 8 weeks. The primary efficacy variable was a mean change from baseline in the number of angina attacks. The secondary efficacy variables were: mean change from baseline in the proportion of patients with no angina attacks, systolic blood pressure, diastolic blood pressure, heart rate, and proportion of blood pressure responders. Number of patients reporting adverse effects (AEs) and severity of AEs in both of the groups were compared.

RESULTS

All patients (n = 100) completed the study. In the S-metoprolol group the number of angina attacks (mean +/- SEM) at baseline and after 2, 4 and 8 weeks of therapy were 6.3 +/- 0.8, 3 +/-0.4, 1.8 +/- 0.4 and 0.7 +/- 0.2, respectively. In the metoprolol group these values were 5.8 +/-1, 3 +/- 0.7, 1.4 +/- 0.3 and 0.7 +/- 0.2, respectively. The reduction in the number of angina attacks from baseline was significant (p < 0.0001) in both groups with no between-group difference. The response rate in angina (percentage of patients completely relieved of angina attacks clinically) was greater in the S-metoprolol group (72%) when compared to the metoprolol group (62%) (p > 0.05, NS). Both study groups showed significant (p < 0.0001) reduction in baseline systolic blood pressure (SBP), diastolic blood pressure (SBP) and heart rate (HR) in hypertensive patients and a clinically non-significant (p > 0.05, NS) change in normotensive patients. Among hypertensive patients, the response rate in angina was higher in the S-metoprolol group (74%) when compared to the metoprolol group (61%) (p > 0.05, NS). In the S-metoprolol group four patients reported AEs: fatigue (n = 4), dry mouth (n = 1), dizziness (n = 1), dyspnea (n = 2), and mild rash (n = 1). In the metoprolol group three patients reported AEs: fatigue (n = 2), dyspnea (n = 1) and dizziness (n = 1). No statistically significant difference was detected between the groups in AE frequency/severity.

CONCLUSION

In routine clinical practice in the management of angina (with or without coexisting hypertension), S-metoprolol administered at half the dose of the racemate, shows similar efficacy, safety and a trend towards a higher response rate.

Tolerability of beta-blockers in outpatients with refractory heart failure who were receiving continuous milrinone

STUDY OBJECTIVE

To investigate the dosing, tolerability, and outcomes associated with the use of concomitant beta-blockers and inotropic therapy in patients with refractory heart failure during the first 6 months of their therapy.

DESIGN

Retrospective review.

SETTING

University-based, tertiary care heart failure and transplant center.

PATIENTS

Sixteen inotrope-dependent outpatients with end-stage refractory heart failure who were receiving continuous intravenous milrinone. Of these patients, 12 also received an oral beta-blocker; the remaining four patients who did not receive beta-blockers served as the comparator group.

MEASUREMENTS AND MAIN RESULTS

For each patient, the initial and final study drug doses of continuous intravenous milrinone and oral beta-blocker treatment, when applicable, were recorded over the 6-month period. Mean heart rate, blood pressure, ejection fraction, and oxygen consumption were measured, and 95% confidence intervals were calculated. Serum sodium and creatinine concentrations, as well as the creatinine clearance, were measured. In the 12 patients who received concomitant milrinone and beta-blockers, the mean baseline ejection fraction was approximately 18%, and they received milrinone for 18.6 weeks. Seven patients received carvedilol for 16.1 weeks, and five received metoprolol tartrate for 17.6 weeks. Dosages of the beta-blockers were titrated. Final daily doses were carvedilol 42.8 mg (95% confidence interval 20.3-65.4) and metoprolol 42.5 mg (95% confidence interval 28.0-57.2). Patients continued to receive other standard oral drug therapy for heart failure. One patient discontinued metoprolol and one discontinued carvedilol because of hypotension and/or worsening heart failure. Cardiac adverse events in the concomitant milrinone plus beta-blocker group were heart failure requiring hospitalization in 10 patients and ventricular arrhythmias in one.

CONCLUSION

Inotrope-dependent patients with refractory end-stage heart failure tolerated continuous intravenous milrinone plus beta-blockers in addition to diuretics and vasodilators for the 6-month observation period. Beta-blocker dosages were titrated, and three patients achieved the target beta-blocker dosage established for stage A-C heart failure. Additional studies are needed to determine the optimal selection and dosing of drug combinations in this population.

Safety of a postoperative beta-blocker infusion protocol for nonmonitored units in a community hospital

OBJECTIVE

To assess the safety of a novel metoprolol infusion protocol implemented on patient care units without cardiac monitoring.

DESIGN

Retrospective chart review.

SETTING

511-bed community teaching hospital.

PATIENTS

100 high cardiac-risk patients undergoing 103 noncardiac surgeries who received 354 infusions.

INTERVENTION

5, 7.5, or 10 mg of metoprolol infused over two hours.

MEASUREMENTS

Infusion dosage and timing, vital signs and adverse events.

RESULTS

A significant decrease in heart rate was demonstrated without any significant adverse events.

CONCLUSION

Our novel metoprolol infusion protocol was safe on nonmonitored units.

NITRIC OXIDE, ERECTILE DYSFUNCTION AND BETA-BLOCKER TREATMENT (MR NOED STUDY): BENEFIT OF NEBIVOLOL VERSUS METOPROLOL IN HYPERTENSIVE MEN

1. Hypertensive men treated with beta-blockers frequently complain of erectile dysfunction. The present study investigated the effects of two beta(1)-adrenoceptor-selective antagonists, namely nebivolol and metoprolol, on erectile function in hypertensive men. 2. Male out-patients (age range 40-55 years) with newly diagnosed or existing stage 1 essential hypertension (mean seated systolic blood pressure 140-159 mmHg; diastolic blood pressure 90-99 mmHg) were enrolled in the study. All patients lived in a stable, heterosexual partnership and had no history of sexual dysfunction. After a 2-week placebo run-in period, patients were randomized double-blind to either Treatment group A (comprising nebivolol 5 mg once daily for 12 weeks, followed by placebo for 2 weeks and then metoprolol succinate 95 mg once daily for 12 weeks) or Treatment group B (comprising metoprolol succinate 95 mg for 12 weeks, placebo for 2 weeks and then nebivolol 5 mg for 12 weeks). An international index of erectile function (IIEF) questionnaire and a diary documented patients' sexual function and activity. 3. Nebivolol and metoprolol lowered blood pressure to a similar extent. Metoprolol, but not nebivolol, significantly decreased the IIEF erectile function subscore by 0.92 in the first 8 weeks after onset of beta-blocker treatment. In contrast with metoprolol, nebivolol improved secondary sexual activity scores and other IIEF subscores. 4. Despite similar antihypertensive efficacy of the cardioselective beta(1)-adrenoceptor antagonists nebivolol and metoprolol, nebivolol may offer additional benefits by avoiding erectile dysfunction in male hypertensive patients on long-term beta-adrenoceptor antagonist therapy.

Plasma concentration of Fas/Fas ligand and left ventricular function in response to metoprolol in conjunction with standard treatment

Recent studies suggest that cardiac myocyte apoptosis contributes to the progress of CHF (congestive heart failure). In the present study, we tested the hypothesis that metoprolol in conjunction with the standard treatment regime for CHF [an ACE (angiotensin-converting enzyme) inhibitor, diuretics and digoxin] may significantly reduce the plasma concentrations of the apoptotic mediators sFas (soluble Fas) and sFasL (soluble Fas ligand) in patients with CHF. An ELISA was used to determine the plasma concentrations of sFas and sFasL in 106 patients with stable CHF at recruitment. Echocardiography was performed at baseline and after 1 year of treatment with metoprolol in conjunction with the standard treatment regime for CHF (i.e. an ACE inhibitor, diuretics and digoxin). The dose of metoprolol was doubled on a biweekly basis up to 50 mg twice a day or maintained at the maximum tolerated dose. Data after 1 year were available for 92 patients and were analysed. The plasma concentrations of sFas and sFasL in patients with CHF decreased significantly (P<0.01) after 1 year of treatment with metoprolol in conjunction with the standard treatment regime compared with at baseline (5.4±0.2 compared with 3.2±0.1 ng/ml respectively for sFas, and 52.1±2.3 compared with 26.7±1.0 pg/ml respectively for sFasL). Compared with baseline, after 1 year of treatment with metoprolol in conjunction with the standard treatment regime there were significant improvements in LV (left ventricular) ejection fraction (from 32.6±0.9 to 51.5±0.8%; P<0.01), LV end-diastolic dimension (from 69.8±0.6 to 57.7±0.3 mm; P<0.01), LV end-systolic dimension (from 53.9±0.6 to 40.5±0.5 mm; P<0.01), LV end-diastolic volume (from 254.7±5.0 to 164.1±2.2 ml; P<0.01) and LV end-systolic volume (from 142.0±4.2 to 72.2±2.0 ml; P<0.01). In addition, the distance walked in a 6-min walk test increased markedly (P<0.01) from 260.3±5.2 m at baseline to 440.9±5.7 m after 1 year of treatment. In conclusion, we have demonstrated that metoprolol in conjunction with an ACE inhibitor, diuretics and digoxin in patients with CHF can lead to a reverse in LV remodelling potentially through its anti-apoptotic effects.

The influence of beta-blockers on delayed memory function in people with cognitive impairment

Adrenergic signaling is important for the retrieval of intermediate-term contextual and spatial memories. The role of norepinephrine in retrieval requires signaling through beta1-adrenergic receptors in the hippocampus. Environmental cues activate the locus ceruleus, the main adrenergic nucleus of the brain, when an environmental stimulus is memorable. This leads to norepinephrine activation in the hippocampus, which is important for retrieving memories. Although beta-blockers do not impair cognition in normal subjects, this article explores the possibility that central nervous system (CNS)-active beta-blockers could affect delayed memory in patients with cognitive impairment. The authors investigated the influence of beta-blockers on delayed memory function in cognitively impaired patients. There was a trend for worse delayed memory retrieval in patients who were on CNS-active beta-blockers. These data support the notion that common medications used in cognitively impaired elderly patients can worsen cognition and that careful selection of medications may help to maximize retrieval of newly formed memories.

Efficacy and safety of extended release metoprolol succinate in hypertensive children 6 to 16 years of age: a clinical trial experience

OBJECTIVE

To evaluate the efficacy, tolerability, and blood pressure (BP) lowering effect of extended release metoprolol succinate (ER metoprolol) in children 6 to 16 years of age with established hypertension.

STUDY DESIGN

Patients were randomized to one of four treatment arms: placebo or ER metoprolol (0.2 mg/kg, 1.0 mg/kg, or 2.0 mg/kg). Data were analyzed on 140 intent-to-treat patients.

RESULTS

Mean age (+/-SD) was 12.5 +/- 2.8 years and mean baseline BP was 132/78 +/- 9/9 mmHg. Following 4 weeks of treatment, mean changes in sitting BP were: placebo = -1.9/-2.1 mmHg; ER metoprolol 0.2 mg/kg = -5.2/-3.1 mmHg; 1.0 mg/kg = -7.7/-4.9 mmHg; 2.0 mg/kg = -6.3/-7.5 mmHg. Compared with placebo, ER metoprolol significantly reduced systolic blood pressure (SBP) at the 1.0 and 2.0 mg/kg dose (P = .027 and P = .049, respectively), reduced diastolic blood pressure (DBP) at the 2.0 mg/kg dose (P = .017), and showed a statistically significant dose response relationship for the placebo-corrected change in DBP from baseline. There were no serious adverse events or adverse events requiring study drug discontinuation among patients receiving active therapy.

CONCLUSION

These data indicate that ER metoprolol is an effective and well-tolerated treatment for hypertension in children.

Acute hemodynamic effects of moderate doses of nebivolol versus metoprolol in patients with systolic heart failure

OBJECTIVES

To determine the acute hemodynamic effect of moderate doses of nebivolol (vasodilating beta1-selective blocker) vs. metoprolol tartrate (non-vasodilating beta1-selective blocker) in systolic heart failure (SHF).

MATERIAL AND METHODS

20 stable patients with SHF (left ventricular (LV) ejection fraction < or = 35%) underwent right heart catheterization. Once a reproducible baseline was obtained, patients were randomized to 5 mg nebivolol PO (n = 10) or metoprolol tartrate 50 mg PO (n = 10). Hemodynamic studies were repeated hourly for the first 4 hours and at 6 hours.

RESULTS

Both agents caused bradycardia. Nebivolol caused additionally a decrease in systemic vascular resistance (SVR) and no significant change in pulmonary capillary wedge pressure (PCWP), and cardiac output (CO). In contrast, metoprolol caused a deterioration of LV systolic function characterized by a decrease in cardiac output, and an increase in SVR and PCWP.

CONCLUSIONS

Treatment initiation with moderate doses of nebivolol is not associated with the adverse hemodynamic effects of metoprolol in patients with SHF. These findings suggest that a long up-titration period may not be necessary with nebivolol.

Effectiveness and tolerability of acupuncture compared with metoprolol in migraine prophylaxis

OBJECTIVES

In a randomized controlled multicenter trial extending over 24 weeks, we investigated whether acupuncture is as effective and safe as metoprolol in the prophylactic treatment of migraine under conditions similar to routine care.

METHODS

One hundred fourteen migraine patients could be randomized to treatment over 12 weeks either with acupuncture (8 to 15 sessions) or metoprolol (100 to 200 mg daily). Main outcome measure was the difference in the number of migraine days between baseline and the weeks 9 to 12 after randomization (derived from a headache diary).

RESULTS

Two of 59 patients randomized to acupuncture withdrew prematurely from the study compared to 18 of 55 randomized to metoprolol. The number of migraine days decreased by 2.5 +/- 2.9 days (baseline 5.8 +/- 2.5 days) in the acupuncture group compared to 2.2 +/- 2.7 days (baseline 5.8 +/- 2.9 days) in the metoprolol group (P= .721). The proportion of responders (reduction of migraine attacks by > or =50%) was 61% for acupuncture and 49% for metoprolol. Both physicians and patients reported fewer adverse effects in the acupuncture group.

CONCLUSIONS

Due to missing the recruitment target (480 patients) and the high drop-out in the metoprolol group the results must be interpreted with caution. Still, they suggest that acupuncture might be an effective and safe treatment option for patients unwilling or unable to use drug prophylaxis.

Effects of metoprolol and carvedilol on pre-existing and new onset diabetes in patients with chronic heart failure: data from the Carvedilol Or Metoprolol European Trial (COMET)

BACKGROUND

Beta blocker treatment may worsen glucose metabolism.

OBJECTIVE

To study the development of new onset diabetes in a large cohort of patients with heart failure treated with either metoprolol or carvedilol.

DESIGN

Prospective and retrospective analysis of a controlled clinical trial.

SETTING

Multinational multicentre study.

PATIENTS

3029 patients with chronic heart failure.

INTERVENTIONS

Randomly assigned treatment with carvedilol (n = 1511, target dose 50 mg daily) or metoprolol tartrate (n = 1518, target dose 100 mg daily).

RESULTS

Diabetic events (diabetic coma, peripheral gangrene, diabetic foot, decreased glucose tolerance or hyperglycaemia) and new onset diabetes (clinical diagnosis, repeated high random glucose level or glucose lowering drugs) were assessed in 2298 patients without diabetes at baseline. Diabetic events occurred in 122/1151 (10.6%) patients in the carvedilol group and 149/1147 (13.0%) patients in the metoprolol group (hazard ratio (HR) = 0.78; 95% confidence interval (CI) 0.61 to 0.99; p = 0.039). New onset diabetes was diagnosed in 119/1151 (10.3%) v 145/1147 (12.6%) cases in the carvedilol and metoprolol treatment groups (HR = 0.78, CI 0.61 to 0.997; p = 0.048), respectively. Patients with diabetes at baseline had an increased mortality compared with non-diabetic subjects (45.3% v 33.9%; HR = 1.45, CI 1.28 to 1.65). Both diabetic and non-diabetic subjects at baseline had a similar reduction in mortality with carvedilol compared with metoprolol (RR = 0.85; CI 0.69 to 1.06 and RR = 0.82; CI 0.71 to 0.94, respectively).

CONCLUSION

A high prevalence and incidence of diabetes is found in patients with heart failure over a course of 5 years. New onset diabetes is more likely to occur during treatment with metoprolol than during treatment with carvedilol.

Factorial antihypertensive study of an extended-release metoprolol and hydrochlorothiazide combination

BACKGROUND

To attain goal blood pressure (BP), many hypertensive patients require combination antihypertensive therapy. Thiazide diuretic/beta-blocker regimens lower BP, and clinical studies indicate that they reduce the risk for cardiovascular consequences of hypertension. Fixed-dose combination tablets can simplify multidrug treatment regimens.

METHODS

This multicenter, randomized, double-blind, placebo-controlled, unbalanced factorial study (N = 1571) was designed to determine whether hydrochlorothiazide (HCT) and extended release (ER) metoprolol both contribute to an antihypertensive effect. Hypertensive adults with sitting diastolic BP (SiDBP) 95 to 114 mm Hg and systolic BP (SiSBP) <180 mm Hg received one of three hydrochlorothiazide doses (6.25 mg, 12.5 mg, or 25 mg), one of four ER-metoprolol doses (25 mg, 50 mg, 100 mg, 200 mg), or one of nine of the combinations or placebo for 8 weeks.

RESULTS

Blood pressure decreased with all combinations (P < .001 v placebo); reductions were dose related, ranging from 8.7 to 15.7 mm Hg (SiDBP) and 9.7 to 18.9 mm Hg (SiSBP) (model-derived values). Reductions with placebo were 5.3 (SiDBP) and 4.2 mm Hg (SiSBP). Both active agents contributed to the combination effect (P = .0015 for SiDBP; P = .0006 for SiSBP). Several low-dose combinations were approximately as effective as high doses of the individual agents (differences within 1 to 2.5 mm Hg). The adverse event discontinuation rate was 2.9%. Serum potassium decreased and uric acid increased with increasing doses of HCT.

CONCLUSIONS

Extended-release metoprolol/hydrochlorothiazide is an effective antihypertensive combination that offers additive antihypertensive contributions from both components.

Autoantibody against beta1-adrenergic receptor and left ventricular remodeling changes in response to metoprolol treatment

Autoantibodies specific for the beta(1)-adrenoceptor (beta(1)-AR) have been implicated in the pathology of congestive heart failure (CHF). We hypothesized that the presence of autoantibodies against beta(1)-AR (anti-beta(1)-AR) is associated with left ventricular (LV) remodelling in response to metoprolol. Synthetic beta(1)-AR peptides served as the target antigen in an ELISA (enzyme-linked immunosorbent assay) were used to screen the sera of 106 CHF patients. Patients were separated into positive (+) anti-beta(1)-AR or negative (-) anti-beta(1)-AR groups according to their anti-beta(1)-AR reactivity. Echocardiography (ECG) was performed at baseline and after one year of metoprolol therapy in combination with standard treatment regime for CHF, that is, digoxin, diuretics and an ACEI (angiotensin-converting enzyme inhibitor). The dose of metoprolol was doubled on a biweekly basis up to 50 mg x 2 daily (b.i.d./day) or attainment of maximum tolerated dose. Ninety-six patients completed final data analysis. Fifty-four patients with (+) anti-beta(1)-AR had greater improvements than 42 patients with (-) anti-beta(1)-AR in LVEDD (left ventricular end-diastolic dimension) (P < 0.01, from 69 +/- 0.8 to 58.0 +/- 0.5 mm vs. 69.0 +/- 0.8-63.6 +/- 0.9 mm) and LVESD (left ventricular end-systolic dimension) (P < 0.01, from 57.1 +/- 1.4 to 43.9 +/- 0.8 mm vs. 56.2 +/- 0.9-48.6 +/- 1.0 mm), and LVEF (left ventricular ejection fraction) (P < 0.01, from 35.4 +/- 1.3 to 49.8 +/- 0.6% vs. 34.4 +/- 1.0-44.3 +/- 1.1%) by metoprolol therapy in combination with standard treatment regime for one year. Of the CHF patients with (+) anti-beta(1)-AR, 65.4% responded to target metoprolol dose as compared to 21.4% of CHF patients without anti-beta(1)-AR (P < 0.01). Response to target metoprolol dose occurred more rapidly in (+) anti-beta(1)-AR than (-) anti-beta(1)-AR of CHF patients (67.5 +/- 2.4 vs. 100.8 +/- 3.0 days, P < 0.01). These results demonstrated that CHF patients with (+) anti-beta(1)-AR had greater improvements in LV remodelling and heart function by metoprolol as compared to (-) anti-beta(1)-AR patients. Moreover, patients with (+) anti-beta(1)-AR have better tolerance to metoprolol therapy than patients without anti-beta(1)-AR.

Phaeochromocytomas presenting as acute crises after beta blockade therapy

OBJECTIVE

Phaeochromocytoma crisis is a life-threatening emergency that may be undiagnosed because of its numerous, nonspecific manifestations. We analysed, retrospectively, the presentation, management and outcome of patients who were admitted to our institution with phaeochromocytoma crises over a 5-year period.

RESULTS

Five patients (two males, three females; mean age 34.6 years, range 19-51 years) who presented as emergencies requiring intensive care, with multiple non-specific manifestations and previously undiagnosed pheochromocytoma, were identified. The initial presentation included features of cardiomyopathy (n = 3), atypical pneumonia with myocarditis (n = 1) and acute abdomen (n = 1). Only one of the five cases had a raised blood pressure at the time of the acute presentation. Initiation of beta blockers in four patients was associated with further deterioration in haemodynamic status, labile blood pressure and cardiac arrhythmias, which led to the diagnosis of the underlying phaeochromocytoma. Following intensive supportive therapy and alpha blockade, all five patients recovered and underwent elective surgical removal of phaeochromocytoma, uneventfully.

CONCLUSION

Unexplained cardiopulmonary dysfunction, particularly after the institution of beta blockers, should alert clinicians to the possibility of phaeochromocytoma. A high index of suspicion is essential to reduce morbidity and mortality in these patients through early diagnosis and aggressive management.