Bradycardia . Decreased heart rate. Bradycardia is considered to be at a heart rate less than 60 ppm (beats per minute) at rest, although it rarely produces symptoms if the rate does not drop below 50 ppm. More specifically, it involves the emission, by the sinus node, of less than 60 ppm, or its lack of total function, in which case the pacemaker rhythm that takes control is that of the atrioventricular node, approximately 20-40 ppm.
It is usually an indication of heart disease, and may also be a symptom of meningitis or other brain injuries. Bradycardia does not necessarily imply the presence of a serious disease, it is not rare in athletes and young adults. It normally occurs during sleep. By itself, it does not require treatment. If instead it is preceded by malnutrition or jaundice or causes fainting, dizziness or weakness, you should suspect a heart condition that should be treated immediately with a cardiologist or internist.
Common causes of a picture of bradycardia may be unstable angina pectoris, essential hypertension , thromboembolic episodes, damage or obstruction of the coronary arteries, or systemic failure of atrial nodes. Bradycardia, likewise, should be taken as the antecedent for a stable heart attack, and even when it occurs in athletes or young adults, it must be carefully evaluated to rule out congenital illnesses or injuries of infectious or chemical origin.
Summary
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- 1 Symptoms
- 2 ETIOLOGY
- 3 DIAGNOSTIC ASSESSMENT
- 4 Signs and tests
- 5 Treatment
- 6 Forecast
- 7 Complications
- 8 Related Links
- 9 Source
Symptoms
- Fainting or passing out
- Vertigo or dizziness
- Confusion or other changes in mental state
- Feeling of perceiving heartbeat (palpitations)
- Chest pain or angina
- Difficulty breathing
- Fatigue
There are usually no symptoms.
PHYSIOPATHOLOGY : alteration of the conduction system at any level a. Sinus node b. AV node c. His- Purkinje
ETIOLOGY
INTRINSECA:
- Congenital
- Degenerative
- Ischemic
- Connective tissue disorder, sarcoidosis, tumors, myocarditis …
EXTRINSECA: • drugs: β-blockers, antiarrhythmics (digoxin …), psychotropic drugs • hydroelectrolytic disorder (hyperkalemia, hypermagnesemia) and endocrine (hypothyroidism) • vagal hypertonia
DIAGNOSTIC EVALUATION
SYMPTOMS AND SIGNS : the form of presentation can be highly variable, including syncopes with a cardiogenic profile, symptoms of heart failure, low expense, or it can be asymptomatic. For all this, it is essential to carry out a complete anamnesis and assess the presence of structural heart disease and prior medical treatment. 2. COMPLEMENTARY EXPLORATIONS: Obtaining ECG, Rx Thorax and Blood analysis with renal function and electrolytes is essential.
Signs and tests
The symptoms are not specific and can be confused with other disorders. The patient’s heart rate can be very slow at any time and the blood pressure can be normal or low.
Sick sinus syndrome can cause or worsen symptoms of heart failure. This syndrome is diagnosed when symptoms occur only during episodes of arrhythmia; however, this is often difficult to prove. An ECG can show various arrhythmias characteristic of this syndrome. Stress tests in particular have not shown efficacy as screening tools.
Holter monitoring is an effective tool to diagnose this syndrome due to the episodic nature of the disorder. During such monitoring, an extremely slow heart rate and long pauses can be observed, along with episodes of atrial tachycardia. An intracardiac electrophysiology study is a very specific test for this disorder, although it is often unable to confirm the diagnosis.
Treatment
No treatment is required if the disorder has no symptoms. The doctor may evaluate the medications the person is taking to make sure they are not making the condition worse. However, no medication should be discontinued unless the doctor has indicated it.
Implantation of a permanent pacemaker may be necessary when symptoms have been determined to be related to bradycardia.
Any tachycardia (rapid heart rate) related to this disorder can be treated with medication after the person is protected from symptomatic bradycardia by an implanted permanent pacemaker. Sometimes a catheter procedure, called radiofrequency ablation, is used to remove the tachycardias.
Forecast
This syndrome evolves slowly. No treatment is required as long as the person continues without symptoms. If a permanent pacemaker is needed, the long-term result is excellent.
Complications
- Insufficient heart pumping
- Heart failure
- Falls or injuries due to fainting
- Angina