Microsomal phosphorylase in rat heart: depletion following adrenalectomy and restoration by in vivo administration of dexamethasone

Possible development and resolution of dilated cardiomyopathy phenotype secondary to atypical hypoadrenocorticism in a dog

OBJECTIVE

To report the possible occurrence of dilated cardiomyopathy phenotype associated with atypical hypoadrenocorticism and subsequent marked improvement with treatment in a mixed breed dog.

CASE SUMMARY

A 4.5-year-old, neutered male mixed breed dog was evaluated for a history and clinicopathological changes consistent with atypical hypoadrenocorticism. The dog was being fed a grain-free diet. While hospitalized for supportive care and diagnostics, the patient developed and was diagnosed with biventricular congestive heart failure secondary to dilated cardiomyopathy phenotype and IV fluid administration. The left-sided congestive heart failure resolved with discontinuation of IV fluid therapy and short-term administration of diuretics. After treatment of atypical hypoadrenocorticism with glucocorticoid supplementation, and while continuing to be fed varying grain-free diets, the patient's dilated cardiomyopathy phenotype largely resolved. The patient fully recovered and did not require any long-term cardiac medications.

NEW OR UNIQUE INFORMATION PROVIDED

Development of dilated cardiomyopathy phenotype has not been described in dogs as a sequela of untreated hypoadrenocorticism but has been reported in human literature. Given the fact that standard management of hypoadrenocorticism typically involves aggressive fluid resuscitation, awareness of this potential sequela is important for patients that fail to respond or develop signs consistent with volume overload.

Takotsubo Cardiomyopathy Secondary to Adrenal Insufficiency: A Case Report and Literature Review

We report a case of a middle-aged female who presented with altered mental status, hypotension, and hypoglycemia and was diagnosed with secondary adrenal insufficiency. She was also found to have elevated troponin I on initial evaluation with diffuse T wave inversions on electrocardiogram. Transthoracic echocardiogram revealed ejection fraction of 38% with apical akinesia. Subsequent left heart catheterization revealed clean coronary arteries. She was diagnosed with typical Takotsubo cardiomyopathy secondary to adrenal insufficiency. She was managed with IV hydrocortisone with resolution of symptoms. This article adds to the select few cases in the literature of the association of Takotsubo cardiomyopathy resulting from secondary adrenal insufficiency.

The Heart of the Matter: Cardiac Manifestations of Endocrine Disease

Endocrine disorders manifest as a disturbance in the milieu of multiple organ systems. The cardiovascular system may be directly affected or alter its function to maintain the state of homeostasis. In this article, we aim to review the pathophysiology, diagnosis, clinical features and management of cardiac manifestations of various endocrine disorders.

Takotsubo-like syndrome triggered by fludrocortisone overdose for Addison's disease: a case report

Background

Reversible left ventricular dysfunction, also termed Takotsubo cardiomyopathy, is rarely reported in Addison’s disease after initiation of hormone replacement therapy. The pathogenesis of this cardiomyopathy is unknown.

Case presentation

A 41-year-old white woman with a history of autoimmune Hashimoto thyroiditis diagnosed 3 years earlier and acute adrenal insufficiency diagnosed 3 weeks earlier presented with new onset of heart failure New York Heart Association class IV, which had started shortly after initiation of hormone replacement therapy with hydrocortisone 20 mg/day and fludrocortisone 0.3 mg/day. Nine days before admission she had collapsed because of dizziness and had a cerebral concussion and open fracture of her nasal bone, however, no further investigations were carried out at that time.

A physical examination revealed leg edema, tachycardia, tachypnea, bilateral basal crepitations, and blood pressure 110/70 mmHg. An electrocardiogram showed sinus tachycardia, low voltage, negative T-waves in V₅ and V₆ and a corrected QT interval of 590 ms. Echocardiography revealed a reduced left ventricular systolic function with an ejection fraction of 30 %, and septal, apical, and anterior wall akinesia. Cardiac magnetic resonance imaging showed relative enhancement of gadolinium, indicating hyperemia and capillary leakage, and no myocardial scars. Because of the improvement in her cardiac function, lack of cardiovascular risk factors, and lack of signs for ischemia on magnetic resonance imaging, no coronary angiography was carried out. The results of sellar and renal magnetic resonance imaging were normal. Her troponin T was slightly elevated. Bisoprolol and ramipril were started. Her fludrocortisone dose was reduced to 0.05 mg/day. Her electrocardiogram and systolic function, documented by echocardiography and magnetic resonance imaging, normalized within 6 months.

Conclusions

Although we could not exclude coronary artery disease by coronary angiography, her clinical course and instrumental findings suggest Takotsubo cardiomyopathy of the apical type. Fludrocortisone overdosage and increased myocardial vulnerability due to cortisol deficiency might be pathogenetic factors, whereas myocarditis is unlikely. When hormone replacement in patients with Addison’s disease is initiated, cardiac function should be monitored by electrocardiogram and echocardiography.

Cardiogenic Pulmonary Edema in a Dog Following Initiation of Therapy for Concurrent Hypoadrenocorticism and Hypothyroidism

A 5 yr old intact female cocker spaniel dog weighing 7.8 kg was referred with anorexia, vomiting, and depression. At referral, the dog was diagnosed initially with typical hypoadrenocorticism, and 2 d later, concurrent primary hypothyroidism was detected. Hormonal replacement therapies, including fludrocortisone, prednisolone, and levothyroxine, were initiated, but a few days later the dog became abruptly tachypneic, and thoracic radiographs indicated the development of pulmonary edema. Echocardiography showed that there were abnormalities indicating impaired left ventricular function, although the heart valves were normal. Following treatment with pimobendan and furosemide, the pulmonary edema resolved. The dog had no recurrence of the clinical signs after 10 mo of follow-up, despite being off all cardiac medications; consequently, the cardiac failure was transient or reversible in this dog. The case report describes the stepwise diagnosis and successful treatment of cardiogenic pulmonary edema after initiation of hormonal replacement therapy for concurrent hypoadrenocorticism and hypothyroidism in a dog.

Lethal arrhythmia and corticosteroid insufficiency

We describe a case of isolated adrenocorticotropic hormone deficiency that showed ventricular fibrillation associated with QT prolongation. A 72-year-old man was admitted because of consciousness disorder caused by severe hypoglycemia. On the second hospital day, QT intervals were unexpectedly prolonged and ventricular fibrillation occurred. Electrical defibrillation was performed and restored hemodynamically stable condition without neurologic deficits. He was diagnosed with endocrine tests as having isolated adrenocorticotropic hormone deficiency. QT prolongation was improved after hydrocortisone replacement therapy. We considered the QT prolongation was caused by corticosteroid insufficiency. We should be aware that corticosteroid insufficiency may provoke QT prolongation responsible for sudden cardiac death.

Takotsubo cardiomyopathy during acute adrenal crisis due to isolated adrenocorticotropin deficiency

We report a 69-year-old woman who had isolated adrenocorticotropic hormone (ACTH) deficiency. Subsequently, she had Takotsubo cardiomyopathy during acute adrenal crisis. Replacement therapy with hydrocortisone sufficiently improved her cardiomyopathy. We conclude that her myocardial dysfunction was closely related to adrenal insufficiency and suggest that in certain circumstances, adrenal crisis may cause Takotsubo cardiomyopathy.

Deficiency of growth hormone in an adult man case of idiopathic adrenocorticotropin deficiency

Growth hormone (GH) deficiency is transient in most cases of adrenocorticotropin (ACTH) deficiency, while deficiency of both selective ACTH and GH in adults, as in the present case, is rare among hypopituitarism cases. In this patient, one year after hydrocortisone replacement for ACTH deficiency, data on GH secretion by insulin tolerance test and GH-releasing peptide-2 injection showed a partial improvement, but still there was lack of an adequate response. We consider that the patient had the deficiency of both selective GH and ACTH. Therefore, careful monitoring of GH function after the glucocorticoid replacement is required in cases of ACTH deficiency.

Ampulla (Takotsubo) cardiomyopathy caused by secondary adrenal insufficiency in ACTH isolated deficiency

We describe here a case of reversible ampulla (takotsubo) cardiomyopathy caused by secondary adrenal insufficiency in ACTH isolated deficiency. A 53-year-old woman was referred to our department for evaluation and treatment of unconsciousness. On admission, her plasma glucose level was 34 mg/dL, suggesting loss of consciousness due to hypoglycemia. Basal levels of ACTH, cortisol, and dehydroepiandrosterone sulfate in blood, and urinary free cortisol levels were all decreased. ACTH and cortisol levels were not adequately increased in response to CRH administration and the insulin tolerance test. Electrocardiography showed ST segment elevation and T wave inversion in leads V 1-6. The coronary arteries were free of organic stenosis, and a left ventriculogram revealed severe hypokinesis, particularly in the anterior and posterior walls. Based on a diagnosis of adrenocortical insufficiency caused by ACTH isolated deficiency, hydrocortisone was administered. Two weeks after treatment, ultrasound studies of the heart showed recovery of left ventricular wall motion. Activation of the sympathetic nervous system, adrenocortical failure, and hypoglycemic attack were considered to be triggering factors for the takotsubo cardiomyopathy. Careful monitoring of cardiac function and appropriate treatments for both cardiomyopathy and adrenocortical failure are required to recover cardiac dysfunction.

Addison's disease presenting with an acute abdomen and complicated by cardiomyopathy

Adrenal insufficiency typically presents with non-specific symptoms, followed by shock secondary to a salt-wasting crisis and/or the vascular effects of glucocorticoid deficiency if it progresses to acute adrenal insufficiency. Rhabdomyolysis and cardiac dysfunction are rarely reported, particularly in children. We report a child with adrenal insufficiency, presenting with acute abdominal signs, probably secondary to rhabdomyolysis, and complicated by reversible cardiomyopathy. Acute adrenal insufficiency should be considered with this presentation. The possibility of impaired cardiac function during its treatment should also be considered.

Cardiac failure and multiple organ dysfunction syndrome in a patient with endocrine adenomatosis

In this case report, we present the successful therapy of severe cardiac failure in pituitary adrenal insufficiency. A previously healthy 56-year-old-man in pituitary coma due to an atypical variant of multiple endocrine adenomatosis (pituitary adenoma and pheochromocytoma) suffered from cardiac failure resistant to catecholamine and standard hydrocortisone therapy. After two bolus injections of dexamethasone (2 x 24 mg) mean arterial pressure and cardiac function dramatically improved, probably due to restoration of permissive effects on catecholamine action and reversal of pathophysiological mechanisms of cardiac failure. We conclude that in patients with severe cardiovascular failure in pituitary coma the administration of potent glucocorticoids may be more effective in reversing cardiovascular failure than standard dosages of hydrocortisone.

Glucocorticoid modulation of protein phosphorylation and sarcoplasmic reticulum function in rat myocardium

To decipher the mechanism(s) underlying glucocorticoid action on cardiac contractile function, this study investigated the effects of adrenalectomy and dexamethasone treatment on the contents of sarcoplasmic reticulum (SR) Ca(2+)-cycling proteins, their phosphorylation by endogenous Ca(2+)/calmodulin-dependent protein kinase II (CaM kinase II), and SR Ca(2+) sequestration in the rat myocardium. Cardiac SR vesicles from adrenalectomized rats displayed significantly diminished rates of ATP-energized Ca(2+) uptake in vitro compared with cardiac SR vesicles from control rats; in vivo administration of dexamethasone to adrenalectomized rats prevented the decline in SR function. Western immunoblotting analysis showed that the relative protein amounts of ryanodine receptor/Ca(2+)-release channel, Ca(2+)-ATPase, calsequestrin, and phospholamban were neither diminished significantly by adrenalectomy nor elevated by dexamethasone treatment. However, the relative amount of SR-associated CaM kinase II protein was increased 2.5- to 4-fold in dexamethasone-treated rats compared with control and adrenalectomized rats. Endogenous CaM kinase II activity, as judged from phosphorylation of ryanodine receptor, Ca(2+)-ATPase, and phospholamban protein, was also significantly higher (50--80% increase) in the dexamethasone-treated rats. The stimulatory effect of CaM kinase II activation on Ca(2+) uptake activity of SR was significantly depressed after adrenalectomy and greatly enhanced after dexamethasone treatment. These findings identify the SR as a major target for glucocorticoid actions in the heart and implicate modification of the SR CaM kinase II system as a component of the mechanisms by which dexamethasone influences SR Ca(2+)-cycling and myocardial contraction.

Adult reversible cardiomyopathy with pituitary adrenal insufficiency caused by empty sella--a case report

The authors report a first case of reversible cardiomyopathy in an adult with adrenal insufficiency. A 62-year-old man was administered to hospital because of congestive heart failure. The electrocardiogram showed prolonged QT interval and negative T wave on the right precordial leads and frequent multifocal ventricular premature contractions. On the echocardiogram, the left ventricle was revealed to be diffusely hypokinetic with remarkable enlargement. 201Thallium single photon emission computed tomography (SPECT) revealed multiple flow defects in the left ventricular wall. He also had pituitary adrenal insufficiency secondary to an empty sella, which was diagnosed by hormonal studies and magnetic resonance images of the brain. After the replacement therapy with hydrocortisone, heart failure was sufficiently resolved. Abnormal flow defects in the myocardium on SPECT were also improved. To the authors' knowledge, adrenal insufficiency with cardiomyopathy has not been previously described in adult patients.

[Myocardiopathy and isolated glucocorticoid deficit with ACTH resistance: a fortuitous association?]

Hereditary syndrome of unresponsiveness to ACTH is a rare autosomal recessive disorder characterized by an isolated glucocorticoid deficiency which is exceptionally associated to regressive cardiomyopathy.

CASE REPORT

A male newborn had iterative episodes of hypoglycemia since the first hours of life. Acute bronchiolitis at the age of 14 days was associated with transitory dilated cardiomyopathy. Hypoglycemia was due to glucocorticoid deficiency secondary to ACTH insensitivity. Molecular biology showed a composite heterozygotism for the ACTH receptor gene.

CONCLUSION

Any congenital glucocorticoid deficiency should lead to search for cardiomyopathy.

Reversible cardiomyopathy in a child with Addison's disease

An 11-year-old boy in acute adrenal crisis was subsequently diagnosed with Addison's disease and presumably had an unrecognized preceding chronic adrenal insufficiency. His adrenal insufficiency and hypovolemic shock were promptly diagnosed and treated in the emergency room. However, 24 h later, signs of congestive heart failure developed and an echocardiogram revealed cardiomyopathy. He responded to i.v. dopamine and his cardiomyopathy resolved over some days. Acute adrenal insufficiency and actual ventricular dysfunction had not been described in humans until last year; this is the second reported case of cardiomyopathy in a patient with acute adrenal insufficiency.

Reversible cardiomyopathy in an infant with unrecognized congenital adrenal hyperplasia

We describe an infant who had a dilated cardiomyopathy and who was later found to have congenital adrenal hyperplasia. The cardiomyopathy resolved after replacement of glucocorticoid and mineralocorticoid. We believe that glucocorticoid deficiency may have played a direct role in the evolution of this cardiomyopathy.