What Is Pacemaker Syndrome?
Pacemaker syndrome is a group of clinical syndromes caused by hemodynamic and electrophysiological abnormalities after pacemaker implantation. Mainly manifested as neurological symptoms, low cardiac output and congestive heart failure, about 38% of patients with syncope in the clinic. Pacemaker syndrome accounts for about 17% to 38% of patients with single-chamber ventricular pacemakers.
Basic Information
- English name
- pacemaker syndrome
- Visiting department
- cardiology
- Multiple groups
- Seniors
- Common locations
- heart
- Common causes
- Atrioventricular syncope loss, atrioventricular valve insufficiency, increased atrial pressure, right ventricular pacing, and ventricular atrial electrical activity
- Common symptoms
- Dizziness, dizziness, syncope, shortness of breath, hypotension, rales in the lungs, edema, jugular vein irritation, heart sounds ranging from palpitations, discomfort, dizziness, etc
Causes of pacemaker syndrome
- 1. Loss of synchronized atrioventricular contraction can reduce cardiac output by 20% to 30%, if the original heart dysfunction can be reduced by more than 50%;
- 2. Atrioventricular valve insufficiency causes systolic blood flow back to the atrium and increases atrial load;
- 3. Increased atrial pressure inhibits the normal contractile reflex of surrounding blood vessels, leading to a decrease in blood pressure;
- 4. Right ventricular pacing causes asynchronous bilateral ventricular contractions;
- 5. Ventricular atrial electrical activity in the atrioventricular reverse conduction.
Clinical manifestations of pacemaker syndrome
- The clinical manifestations of pacemaker syndrome are mainly a series of symptoms and signs caused by low cardiac output. However, the performance of different individuals is not consistent due to their different compensatory capacity for cardiac function. Generally speaking, older people are more common.
- Symptoms
- (1) Dizziness Dizziness can occur in most patients with pacemaker syndrome.
- (2) Vertigo. Paroxysmal vertigo can occur in about 85% of patients.
- (3) Syncope A syncope may occur in about 49% of patients. Syncope occurred in 38% of patients.
- (4) Shortness of breath, dyspnea, palpitations, drowsiness, and chest pain.
- 2. Signs
- (1) Hypotension Hypotension is one of the important signs of pacemaker syndrome, with an incidence of about 25%. Some patients show orthostatic hypotension, and some show fluctuations in blood pressure.
- (2) Signs of congestive heart failure Approximately 30% of patients with pacemaker syndrome can present with signs of congestive heart failure such as lung rales, edema, and jugular vein distension.
- (3) Changes in heart sounds and heart murmurs Heart sounds can vary in intensity, irregular heart sound rhythms, and heart murmurs appear during pacing.
- (4) Liver pulsation.
- Pacemaker syndrome is usually caused by VVI pacing, but it can also occur in AAI (suppressed on-demand atrial pacing) or frequency-adaptive atrial pacing (AAIR). The latter is mainly manifested in the increased pacing frequency after the activity, and symptoms of low cardiac output such as palpitations, discomfort, and dizziness. The main reason is the patient's atrioventricular nodal dysfunction, and the AAIR pacing appears atrioventricular block and ventricle Slow rate, insufficient cardiac output.
Pacemaker syndrome
- Examination of electrophysiological and hemodynamic indicators:
- ECG physiological index
- After ventricular pacing, atrioventricular retrograde conduction and symptoms occurred, but symptoms stopped after pacing was stopped or the atrioventricular order was changed.
- 2. Hemodynamic indicators
- During ventricular pacing, arterial pressure decreased by 20-30 mmHg, pulmonary capillary wedge pressure and right atrial pressure increased significantly by more than 20 mmHg, and symptoms appeared at the same time.
Pacemaker syndrome diagnosis
- The main premise for establishing the diagnosis of pacemaker syndrome is that the patient has symptoms after the VVI artificial pacemaker has been placed; the pacemaker function is normal; hemodynamic abnormalities such as decreased blood pressure and stroke volume, and veins during cardiac pacing Pressure and lung blunt pressure increased; symptoms reduced or disappeared when the heart rhythm appeared.
Differential diagnosis of pacemaker syndrome
- Nervous system diseases and intolerance of patients who do not adapt to pacing therapy in the short term need to be ruled out. Patients with normal pacing function and recurrent syncope or congestive heart failure should undergo further intracardiac electrophysiological examination and hemodynamic examination.
Pacemaker syndrome complications
- 1. Repeated syncope due to the loss of synchronized atrioventricular contraction, reducing cardiac output by 20% to 30%. If the patient's original heart dysfunction, the cardiac output can be reduced by more than 50%.
- 2. Congestive heart failure Due to the simultaneous loss of atrioventricular contraction after implantation of a pacemaker into the ventricle, atrial pressure rises and the load increases, which reduces the amount of cardiac output and congestive heart failure.
- 3. Hypotension After implantation of a ventricular pacemaker, as the atrioventricular contraction is not synchronized, the atrial dilatation and pressure increase, followed by a decrease in reflex peripheral vascular resistance and a decrease in blood pressure.
Pacemaker Syndrome Treatment
- Switch to atrioventricular sequential two-chamber pacing. Atrioventricular sequential pacing synchronized recovery of atrioventricular sequential contraction and cardiac output increased, but in practical applications, cardiac output and peripheral resistance were found to improve.
Pacemaker Syndrome Prognosis
- The mechanism of pacemaker syndrome is very clear, as long as the pacemaker and pacemaker are correctly selected for the patient, this situation can be avoided. Once the pacemaker syndrome occurs, the prognosis is better after proper treatment.
Pacemaker Syndrome Prevention
- Try to use physiological dual-chamber pacing. For patients receiving VVI pacing, if the blood pressure decreases by more than 20mmHg after implantation, it is likely that pacemaker syndrome will occur, and a dual-chamber pacemaker should be implanted.