B.27 Non-Pharmacological TX of Arrhythmias Flashcards
B.27 Non-Pharmacological TX of Arrhythmias
What is the first step
Begin with electrophysiological mapping to identify the foci responsible for the arrhythmia.
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation
- In medical terminology, ablation refers to the removal of tissue.
- Involves the destruction of small areas of cardiac tissue using electrical energy delivered through an intracardiac catheter.
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation
Radiofrequency (RF) Energy
- Cells are destroyed by heating to over 50 degrees Celsius.
- The RF generator alternates between 500-750 kHz using the active catheter and a large indifferent electrode placed on the patient’s skin.
- Ions adjacent to the catheter are agitated, generating heat. The heat decreases significantly as the distance from the catheter increases.
- Important temperature thresholds:
- Below 50 degrees Celsius: transitory loss of function.
- 50 degrees Celsius and above: permanent damage.
- Above 80 degrees Celsius: coagulation (thromboboembolism).
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation Cooled RF
- The catheter tip is cooled by blood flow during RF application, ensuring that the hottest part of an RF lesion is located just 1 mm below the surface.
- As the lesion forms, blood flow stagnates, causing an increase in temperature, which limits the power delivered and the size of the lesion.
- Introducing saline through a lumen at the catheter tip permits higher power levels and larger lesions to be created, which is essential when the myocardium is thick.
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation Cryoablation
- Liquid nitrous oxide is injected into the catheter tip, where it quickly vaporizes and extracts heat from the tissue in contact with the catheter.
- The gas is swiftly returned to the catheter console.
- Tissue temperature drops to -30 degrees Celsius, resulting in reversible loss of cell function. Further cooling to -60 degrees Celsius for 4 minutes can lead to permanent destruction of the tissue.
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation Indications
- AVNRT (success rate exceeds 97%)
- AVRT (Wolff-Parkinson-White syndrome)
- Atrial flutter
- Atrial tachycardia
- Monomorphic ventricular tachycardia
- Atrial fibrillation (in selected cases)
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation Complications
- Death
- Stroke
- Cardiac tamponade
- AV-node block
- Coronary artery spasms
- Myocardial infarction (MI)
- Pneumothorax (noted only with subclavian approach for catheter placement)
- X-ray exposure
- Pericarditis
- Recurrence of arrhythmia (1-10%)
- Cardiac perforation (less than 1%)
B.27 Non-Pharmacological TX of Arrhythmias
Catheter Ablation Advantages
- Reduces the frequency of abnormal heart rhythms in the ventricles, subsequently decreasing the number of ICD shocks a patient may receive.
- High success rate
- Well-defined lesion
- No adverse hemodynamic effects
- Short recovery time
- Repeatable procedure
- Cost-effective
B.27 Non-Pharmacological TX of Arrhythmias
CRT – Cardiac Resynchronization Therapy
Cardiac Resynchronization Therapy (CRT) is a specialized treatment for heart failure patients who also have an abnormal heart rhythm, particularly those with left ventricular dyssynchrony (a condition where the heart’s chambers do not beat in sync). Here’s a summary of CRT:
- Purpose: CRT aims to improve the efficiency of the heart’s pumping action by coordinating the contractions of the heart’s ventricles. This synchronization enhances cardiac output and reduces symptoms of heart failure.
- Indications: CRT is typically indicated for patients with heart failure who have a reduced ejection fraction (less than 35%) and exhibit a specific type of arrhythmia known as wide QRS complex (a prolonged interval on an ECG that indicates dyssynchrony).
- Device Components: CRT involves the implantation of a specialized pacemaker, known as a CRT device, which includes leads placed in the right ventricle and typically one or two leads implanted in the left ventricle via the coronary sinus.
- Procedure: The implantation is done in a hospital setting, often under local anesthesia or sedation. The device monitors the heart’s activity and provides electrical stimulation to the ventricles to ensure they contract simultaneously or in a more coordinated fashion.
- Benefits: Patients receiving CRT often experience improved symptoms such as reduced shortness of breath and fatigue, enhanced exercise capacity, and a better quality of life. CRT can also lead to fewer hospitalizations and overall better heart function.
- Follow-Up: Regular follow-up is required to ensure the device is functioning correctly, make necessary adjustments, and monitor for any potential complications.
In summary, CRT is an effective therapeutic option for patients with heart failure and arrhythmias, significantly improving the synchronization of heart contractions, enhancing quality of life, and reducing hospitalization rates associated with heart failure.
B.27 Non-Pharmacological TX of Arrhythmias
Pacemaker
Pacemaker treatment for arrhythmia involves the implantation of a pacemaker device to regulate an abnormal heart rhythm. This treatment is particularly beneficial for individuals with arrhythmias such as bradycardia (slow heart rate) or other rhythm disorders that lead to ineffective heartbeats.
- Function: The pacemaker continuously monitors the heart’s electrical activity. When it detects a heart rate that is too slow or an irregular rhythm, it sends electrical impulses to stimulate the heart to beat at a normal rate. This ensures that blood is pumped effectively throughout the body.
- Types: There are several types of pacemakers, including single-chamber, dual-chamber, and biventricular pacemakers. The choice depends on the specific condition of the patient and the nature of their arrhythmia.
- Procedure: The implantation of a pacemaker is typically done under local anesthesia and involves placing leads in the heart via a vein. The pulse generator is then implanted under the skin of the chest.
- Benefits: Pacemakers improve symptoms associated with arrhythmias, such as fatigue, dizziness, and fainting. They enhance overall quality of life by restoring a normal heart rhythm, which is crucial for proper heart function and oxygen delivery to the body.
- Follow-Up: Regular follow-up appointments are necessary to ensure the pacemaker is functioning properly and to make any necessary adjustments.
Overall, pacemaker therapy is a safe and effective treatment option for managing certain types of arrhythmias, significantly improving patient outcomes.
B.27 Non-Pharmacological TX of Arrhythmias
Electrical cardioversion
Electrical cardioversion is a medical procedure used to restore a normal heart rhythm in patients experiencing certain types of arrhythmias, particularly atrial fibrillation or atrial flutter. Here’s a brief summary of the treatment:
- Purpose: The primary aim of electrical cardioversion is to convert a fast or irregular heartbeat back to a normal sinus rhythm. It is typically used when medications are ineffective or when rapid intervention is necessary to prevent complications.
- Procedure: The procedure involves delivering a controlled electrical shock to the heart through pads placed on the chest (and sometimes on the back). This shock interrupts the chaotic electrical activity in the heart, allowing it to reset and restore a normal rhythm.
- Anesthesia: Electrical cardioversion is usually performed under sedation or general anesthesia to ensure patient comfort during the procedure.
- Indications: It is commonly indicated for patients with atrial fibrillation or atrial flutter, especially if they are experiencing symptoms like palpitations, shortness of breath, or chest pain. It can also be used in life-threatening arrhythmias such as ventricular tachycardia.
- Post-Procedure Care: After the procedure, the patient is monitored for a short period to assess heart rhythm and any immediate complications. Patients may be prescribed anticoagulants if atrial fibrillation was present to prevent blood clots.
- Effectiveness: Electrical cardioversion is generally a safe and effective method for restoring normal rhythm, with a high success rate for converting atrial fibrillation to sinus rhythm.
In summary, electrical cardioversion is a crucial intervention for managing certain arrhythmias, providing quick relief from symptoms and reducing the risk of stroke or other complications associated with arrhythmic conditions.
B.27 Non-Pharmacological TX of Arrhythmias
Implantable Cardioverter Defibrillator (ICD) Treatment for Arrhythmias
- Purpose: The ICD is designed to monitor and treat potentially life-threatening arrhythmias, particularly ventricular tachycardia and ventricular fibrillation, which can lead to sudden cardiac arrest.
- Indications: ICDs are recommended for patients with a history of life-threatening arrhythmias, those with significant heart disease, or patients who are at high risk for arrhythmias due to genetic conditions or previous heart events.
- Device Components: The ICD consists of a pulse generator implanted under the skin, usually in the chest, and one or more leads placed into the heart through veins. This allows for continuous monitoring of the heart’s rhythm.
- Functionality: If the device detects a dangerous arrhythmia, it can deliver electric shocks to restore a normal heart rhythm (defibrillation) or provide pacing therapy to correct less severe arrhythmias.
- Procedure: The implantation is typically performed in a hospital under local anesthesia or conscious sedation. Recovery time varies, but patients are usually monitored for a short period before discharge.
- Benefits: ICDs can significantly improve survival rates in patients at risk of sudden cardiac arrest by providing timely intervention during life-threatening arrhythmias.
- Follow-Up: Regular check-ups are necessary to ensure the device is functioning correctly and to assess the patient’s overall heart health.
In summary, ICDs play a crucial role in managing serious arrhythmias, offering protection and improving outcomes for high-risk patients.
