Hyperparathyroidism cardiomyopathy

Introduction to hyperparathyroidism Hyperparathyroidism (parathyroidism) is a group of syndromes characterized by hypercalcemia and hypophosphatemia caused by excessive secretion of parathyroid hormone (PTH), mainly characterized by extensive bone decalcification and urinary system. Multiple stones and renal tubular function are impaired, neuromuscular stress is reduced, and there are cardiovascular system involvement, including hypertension, arrhythmia, cardiac calcification and myocardial ischemia. basic knowledge The proportion of illness: the incidence rate is about 0.002% - 0.007% Susceptible people: no special people Mode of infection: non-infectious Complications: hypertension, angina, arrhythmia, renal failure, heart failure

Causes of hyperparathyroidism

(1) Causes of the disease

Among the causes of hyperparathyroidism: parathyroid adenomas accounted for 85%; parathyroid hyperplasia accounted for 12%; parathyroid carcinoma accounted for 3%.

(two) pathogenesis

PTH has a positive force, a time-varying effect on the heart, and changes with the extracellular calcium concentration. PTH binds to a specific receptor on the cardiomyocyte membrane, activates adenylate cyclase, and in the presence of magnesium, ATP Conversion to cAMP, cAMP activates inactive protein kinases, which in turn activates phosphorylase, causes changes in permeability of cardiomyocytes, promotes calcium entry into cardiomyocytes, triggers the process of excitation-contraction coupling, and PTH has a direct excitatory effect on the heart. Moreover, it can increase the release of endogenous norepinephrine in the myocardium, and has synergistic effects with isoproterenol and adrenaline.

Hyperparathyroidism due to excessive secretion of PTH and hypercalcemia, increased heart rate, increased oxygen consumption, excessive calcium overload can cause vasospasm, when blood calcium is greater than 3.75mmol / L, occurs Migratory calcification, calcium deposition in soft tissue, when calcium is deposited in the intima and media of the coronary arteries, can cause stenosis of the lumen, resulting in increased blood pressure, angina and even myocardial infarction. Another important factor in the development of hypertension is renal calcium deposition. Caused by renal insufficiency, hypercalcemia can also cause myocardial interstitial calcium deposition, myocardial calcium overload, can interfere with mitochondrial cell respiration, activate myocardial enzymes, damage cell membrane, induce arrhythmia, stimulate oxygen free radical production, etc. This causes irreversible damage to the myocardium and even congestive heart failure.

Parathyroid hyperthyroidism prevention

1. The cause of primary hyperparathyroidism is unclear and lacks effective prevention. However, patients with potential risk factors, such as those with thyroid disease who have undergone radiotherapy, should be monitored, detected early, treated in time to prevent disease. Develop in depth.

2. There are different treatment opinions for mild patients (only those with mild blood calcium and no clinical symptoms), and some advocate active surgical treatment (surgery should be performed under 70 years old; conservative treatment should be given for children over 70 years old). It can be treated conservatively. For patients with obvious clinical symptoms, surgical treatment should be actively carried out to effectively control its hyperfunction to prevent the occurrence and development of complications. After surgery, it actively treats hypocalcemia and monitors blood calcium.

3. Prevention and treatment of hypercalcemia crisis

Increased blood calcium levels, exceeding 3.75mmol / L (15mg / dl), can appear hypercalcemia crisis, life-threatening, at this time, should be actively treated with calcium reduction to prevent the occurrence of crisis.

4. Active prevention of hyperparathyroidism, kidney stones, bone disease and calcium arthritis.

Complications of hyperparathyroidism Complications hypertension angina pectoris arrhythmia renal failure heart failure

Hypertension, angina pectoris, arrhythmia, renal failure, heart failure and other complications can occur.

Symptoms of hyperparathyroidism Cardiomyopathy Common symptoms Drinking polyuria Constipation Dizziness Parathyroid function Hyperactivity Tachycardia Bradycardia Heart failure Congestion Osteoporosis

Clinical manifestation

The skeletal system mainly includes the body bone, joint pain, general osteoporosis, multiple fibrous osteitis and pathological fractures, urinary system with polyuria and thirst, polydipsia, multiple renal and ureteral stones, and renal function in the late stage. Impaired, neuromuscular excitability decreased as a result of fatigue, nausea, vomiting, bloating, constipation, and some patients with acute pancreatitis and ulcer disease.

2. Cardiovascular system performance

About 50% of patients with hyperparathyroidism have high blood pressure, accompanied by headache, dizziness, and the severity of hypertension is related to the degree of renal insufficiency. Patients with hyperparathyroidism may have multiple arrhythmias, and the typical electrocardiogram shows a shortened QT interval. There may be tachycardia, bradycardia, atrioventricular block, ventricular premature contraction, and even sudden ventricular tachycardia. Myocardial ischemia is not uncommon. Slarich et al reported a 50-year-old female patient with a parathyroid. Adenoma, blood calcium is 3.0mmol / L, frequent angina pectoris, nifedipine can relieve symptoms, when the tumor is removed, blood calcium drops to normal, angina completely disappears, Katz also reported a 62-year-old male, primary nail Paralyzed patients, blood calcium up to 4.2mmol / L, acute renal failure occurred in the course of 10 weeks, congestive heart failure, and finally died of myocardial infarction, autopsy found only mild sclerosis of the coronary arteries, microscopic myocardial arterioles The middle layer is extensively calcified, partially occluded, and diffuse scar formation and fibrosis in the left ventricle. Two parathyroid glands are seen, which are hyperplastic under the microscope. This example shows the clinical significance of cardiac calcification.

Examination of hyperparathyroidism

1. Hypercalcemia with hypophosphatemia is one of the most important criteria for the diagnosis of hyperparathyroidism. The blood calcium value is determined by multiple times >2.5mmol/L; the blood phosphorus is low.

2. Serum AKP increased, renal phosphorus reabsorption rate decreased, serum immune activity PTH increased.

3. ECG

Typical manifestations are shortened QT interval, tachycardia, bradycardia, atrioventricular block, ventricular premature contraction, and even ventricular tachycardia.

4 ultrasonic fault

Parathyroid adenoma showed a mass ultrasound image, the echo was diffuse, subtle, and the intensity was low. Adenomas with a diameter of 5 mm or more were found, and the false positive rate was 4%.

5 radionuclide scanning

About 60% of parathyroid tumors can occur, but small adenomas of 2.0 g or less are prone to omission.

Diagnosis and differentiation of hyperparathyroidism

Mainly based on clinical manifestations and laboratory tests, if there is excessive serum calcium, low blood phosphorus, elevated serum AKP, decreased renal tubular phosphorus absorption rate, increased serum immune activity PTH and other laboratory evidence, combined with clinical manifestations can be diagnosed, B Ultra and radionuclide scans help to find the cause.

Differential diagnosis

1. Exclude hypercalcemia caused by other causes.

Pay attention to the identification of diseases such as vitamin AD poisoning, hyperthyroidism, Edison disease, tumor, sarcoidosis, multiple myeloma.

2. Different from cardiomyopathy and myocarditis.

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