Overview.
Sinusoventricular conduction, alias sinus rhythm; diffuse complete atrioventricular myocardial block; high-potassium diffuse complete atrioventricular myocardial block combined with high degree of intraventricular block; increased potassium appearing in muscle weakness and even paralysis formation. Increased potassium appears in muscle weakness and even paralysis formation. It usually occurs more frequently in the lower limbs, and later extends along the trunk to the upper limbs; the respiratory muscles may be involved only in rare cases. The main cause of the disease is hyperkalemia, and sinusoventricular conduction may occur from all causes of hyperkalemia. Winkler reported that when potassium is elevated to 5-7 mmol/L, the electrocardiogram shows a sharp T-wave and an absent P-wave. However, the electrocardiographic changes associated with elevated potassium can vary from one individual to another.
Etiology
Sinusoventricular conduction may occur mainly due to hyperkalemia, which is caused by a variety of reasons. It is not clear how high the blood potassium value increases before sinusoventricular conduction occurs. Winkler reported that when the blood potassium increases to 5-7 mmol/L, the electrocardiogram shows that the T-wave becomes sharp and the P-wave disappears, but the electrocardiogram changes that occur with the increase of blood potassium may vary from individual to individual.
Symptoms
Increased potassium appears in muscle weakness or even paralysis formation. It usually occurs more frequently in the lower limbs, and later extends along the trunk toward the upper limbs to the respiratory muscles, which may be involved only in rare cases.
Examination
Electrocardiogram (ECG) has the following characteristics: P wave disappears, QRS wave is wide and distorted, T wave is high and symmetrical, resembling ventricular escape rhythm or accelerated ventricular escape rhythm, or resembling atrioventricular rhythm with intraventricular conduction disorders. If the patient is observed carefully, the corresponding dynamic changes of P wave, QRS wave, and T wave can be seen with the gradual elevation of potassium in the blood. If potassium continues to rise and the condition progresses, the QRS wave time limit may become more and more prolonged, and the T wave tends to be reduced and rounded, becoming sinusoidal and even evolving into slow-type ventricular fibrillation.
Diagnosis
1. Clinical hyperkalemia and the etiology of hyperkalemia.
2. A series of wide and abnormal QRS wave clusters with elevated and symmetrical T waves.
Treatment
Sinusoventricular conduction is seen in hyperkalemia caused by various etiologies, and most of them are critically ill patients who can die from hyperkalemia and its fatal arrhythmia if not rescued in time.
1. Treatment of etiology: the etiology of hyperkalemia mainly includes various causes of renal decompensation or renal failure, uremia, diabetic nephropathy, hemolytic disease, massive blood transfusion, hypervolemic shock, extensive burns, crush injuries, and various causes of metabolic acidosis, etc. We should actively treat the primary disease and promote the reduction of blood potassium.
2. Measures to rapidly reduce blood potassium in the treatment of hyperkalemia are:
(1) 10% calcium gluconate 10ml, intravenous slow injection;
(2) Furosemide (tachycardia) or etanercept (sodium diuretic acid) and other rapid potassium-removing diuretics, and saline corticosteroids can be given at the same time as appropriate;
(3) 60 ml of 50% glucose solution with 10 U of insulin, injected slowly intravenously;
(4) Hypertonic alkaline solution, such as 4% sodium bicarbonate solution 40 ml or 11.2% sodium lactate 20-40 ml intravenous slow injection. It is especially suitable for hyperkalemia with metabolic acidosis;
(5) Peritoneal dialysis or hemodialysis is feasible;
(6) Blood potassium and ECG should be monitored during treatment.
Prevention
1. Treatment and prevention of the primary disease causing hyperkalemia is the key to preventing the disease. When encountering diseases that may cause hyperkalemia in the clinic, the patient’s blood potassium concentration and electrocardiogram changes should be closely monitored in the course of treatment.
2. Effective treatment should be carried out actively to prevent the occurrence of serious consequences when an increase in blood potassium is detected.