Cardiac Procedures, Devices, and Related Terms

Catheter Ablation (Radio-frequency or Cryoablation)

• Definition: A minimally-invasive procedure that treats abnormal heart rhythms (arrhythmias) by disrupting specific cardiac tissue.

  • Description: Utilizes a catheter (radio-frequency heats, cryoablation freezes) to target and ablate cardiac tissue generating faulty electrical impulses, often for long-term rhythm control.

Cardiac Resynchronisation Therapy (CRT / Biventricular Pacemaker)

• Definition: A special pacemaker therapy for heart failure patients with ventricular dyssynchrony, where ventricles contract asynchronously.

  • Description: Implants a device with three leads to coordinate ventricular contractions, improving cardiac output and reducing heart failure symptoms. CRT-D variants also include ICD capability.

Cardioversion (Rhythm-restoration Technique)

• Definition: A procedure to convert abnormal heart rhythms (e.g., atrial fibrillation/flutter) back to normal sinus rhythm.

  • Description: Can be Electrical, involving synchronized shocks under general anaesthetic, or Pharmacological, using anti-arrhythmic drugs via IV or oral administration.

Coronary Angioplasty & Percutaneous Coronary Intervention (PCI)

• Definition: A catheter-based procedure to open narrowed or blocked coronary arteries.

  • Description: A balloon at the catheter tip is inflated within the stenosed artery to compress plaque, often followed immediately by stent deployment to maintain patency. Used for angina or heart attacks.

Defibrillation & Automated External Defibrillators (AEDs)

• Definition: Delivery of an unsynchronised electrical shock to "re-boot" the heart during cardiac arrest (ventricular fibrillation/pulseless VT).

  • Description: AEDs are portable, automated devices designed for layperson use, democratizing lifesaving technology. Planned defibrillation is essentially electrical cardioversion in a hospital setting.

Extracorporeal Membrane Oxygenation (ECMO)

• Definition: An external circuit that provides mechanical circulatory and respiratory support by oxygenating blood and removing CO₂.

  • Description: Used in severe conditions like refractory cardiogenic shock or catastrophic respiratory failure, serving as a bridge to recovery, transplantation, or decision-making in specialized care centers.

Coronary Artery Bypass Graft (CABG) Surgery

• Definition: An open-heart surgical procedure to bypass blockages in coronary arteries.

  • Description: Involves harvesting conduits (e.g., internal mammary artery) and surgically grafting them to bypass diseased segments, improving blood flow, relieving angina, and reducing future MI risk, especially for complex disease.

Heart Transplant

• Definition: Surgical replacement of a diseased heart with a healthy donor heart.

  • Description: Reserved for end-stage heart failure unresponsive to maximal therapy, requiring rigorous evaluation due to the very limited number of donor hearts available. Ventricular assist devices (VADs) often bridge waiting times.

Balloon Valvuloplasty / Valvotomy

• Definition: A minimally-invasive procedure to dilate stenotic (narrow) heart valves.

  • Description: A balloon catheter is passed through the narrowed valve and inflated to crack fused commissures, most commonly used for mitral stenosis in younger patients. If unsuccessful, surgical repair or replacement may be needed.

Heart Valve Surgery & Transcatheter Aortic Valve Implantation (TAVI)

• Definition: Procedures for repairing or replacing defective heart valves.

  • Description: Conventional surgery involves open repair or replacement with mechanical (durable, requires lifelong anticoagulation) or biologic (limited durability, less anticoagulation) prostheses. TAVI is a catheter-based deployment of a new aortic valve, favored for high-risk or inoperable aortic stenosis patients.

Implantable Cardioverter-Defibrillator (ICD)

• Definition: A small implanted device designed to monitor intracardiac rhythm and deliver therapy for life-threatening arrhythmias.

  • Description: Functions include over-drive pacing to terminate tachycardia, high-energy shocks for VT/VF, and backup pacing for bradycardia. It stores electrograms for review and comes in various types (single/dual/biventricular, subcutaneous).

Intra-Aortic Balloon Pump (IABP)

• Definition: A temporary mechanical assistance device that augments coronary perfusion and reduces afterload.

  • Description: A balloon placed in the descending thoracic aorta inflates during diastole (boosting perfusion) and deflates just before systole (reducing afterload). Used for temporary support in cardiogenic shock or peri-operative low-output states.

Pacemaker (Artificial)

• Definition: An implanted electronic device that delivers small electrical pulses to maintain an adequate heart rate when the natural pacemaker (SA node) fails.

  • Description: Consists of a generator and leads, implanted subcutaneously. Requires routine follow-ups for device interrogation and battery longevity (5-15 years), allowing a near-normal lifestyle.

Thrombolysis ("Clot-busting" Therapy)

• Definition: Administration of fibrinolytic agents to dissolve blood clots.

  • Description: Indicated for acute ST-elevation myocardial infarction (STEMI) when PCI is unavailable within guideline timeframe. Intravenous drugs dissolve coronary thrombus to restore blood flow, but carry risks, notably bleeding.

Ventricular Assist Devices (VADs)

• Definition: Mechanical pumps surgically attached to one or both ventricles to augment systemic blood flow.

  • Description: Used as a 'bridge' to transplant or recovery, or as 'destination therapy' for non-transplant candidates. Components include an internal pump and external controller/battery pack, improving survival and quality of life while requiring specific lifestyle adaptations.