A small implanted device that watches the heart and paces it when it slows below a programmed rate. Modern options include traditional transvenous, leadless capsules, and resynchronization (CRT-P) pacemakers. Performed by Ilyas K. Colombowala, MD, FACC, FHRS, board-certified cardiac electrophysiologist serving Northwest Houston and surrounding communities.
A new procedure center at the Texas Medical Center
The Advanced Cardiovascular Institute at the Texas Medical Center, at 6624 Fannin St, Houston, TX 77030, opens in June 2026, our new ambulatory surgery center for cardiac electrophysiology. It will perform catheter ablation, pacemaker, ICD, and loop recorder procedures in the Texas Medical Center for the comfort and convenience of our patients.
Consultations and follow-up continue at our Hargrave Rd clinic in Northwest Houston, with procedures performed at the most appropriate location: Houston Methodist Willowbrook, Houston Methodist Cypress, Baylor St. Luke’s Medical Center, St. Luke’s The Vintage, Memorial Hermann Memorial City, or the new TMC ASC. Learn more → or call (832) 478-5067 to schedule.
Who needs a pacemaker
Pacemakers treat slow heart rhythms that cause symptoms, fatigue, lightheadedness, fainting, exercise intolerance, or that present a safety risk. The most common indications are sinus node dysfunction (the heart's natural pacemaker can't keep up), AV block (the electrical signal from the upper chambers can't reach the lower chambers reliably), and atrial fibrillation with a slow ventricular response.
Pacemakers do not speed your heart up if your rate is already normal. They pace only when needed.
Traditional transvenous pacemakers
The traditional pacemaker has a small generator under the skin near the collarbone and one or two thin leads that travel through a vein into the heart. A one- to two-hour procedure under local anesthesia and conscious sedation. Most patients go home the same day or after one night.
Leadless pacemakers: Micra and Aveir
For patients who only need ventricular pacing or whose vascular access is challenging, leadless pacemakers offer a meaningful alternative. The device is about the size of a large vitamin capsule and lives entirely inside the right ventricle, no chest scar, no wires through veins.
Two systems are FDA-approved: Medtronic Micra (single-chamber VVI or VDD-like VVI with mechanical atrial sensing) and Abbott Aveir (single- and dual-chamber configurations). We implant both.
Cardiac resynchronization (CRT-P)
For patients with reduced heart-pumping function (heart failure with reduced ejection fraction) and a wide QRS on ECG, a CRT-P pacemaker can resynchronize the contraction of the left and right ventricles. Significant symptomatic and mortality benefit in well-selected patients.
Pacemakers are for slow heart rhythms that cause symptoms such as fatigue, lightheadedness, fainting, or poor exercise tolerance, or that pose a safety risk. The most common reasons are sinus node dysfunction, AV block, and atrial fibrillation with a slow heart rate. A pacemaker only paces when your rate drops too low; it does not speed up a normal heart.
What is a leadless pacemaker, and am I a candidate?
A leadless pacemaker is a self-contained capsule about the size of a large vitamin that sits inside the heart with no chest incision and no wires through the veins. It suits patients who need ventricular pacing or who have difficult vein access. Dr. Colombowala implants both FDA-approved systems, the Medtronic Micra and the Abbott Aveir.
How long does pacemaker implantation take, and what is recovery?
A traditional pacemaker is placed in about one to two hours under local anesthesia with sedation, through a small incision near the collarbone. Most patients go home the same day or after one night. Movement of the arm on that side is limited for a few weeks while the leads settle.
What is the difference between a pacemaker and a defibrillator (ICD)?
A pacemaker treats slow heart rhythms by gently pacing the heart when it falls behind. An ICD watches for dangerous fast rhythms and can deliver a shock to prevent sudden cardiac arrest. Some patients need both functions, which can be combined in a single device.
What is a CRT pacemaker?
A CRT-P, or cardiac resynchronization pacemaker, coordinates the contraction of the left and right ventricles in patients with weakened heart-pumping function and a wide QRS on the ECG. In well-selected patients it improves symptoms and survival. Whether CRT is right for you depends on your ejection fraction and ECG pattern.
