Cardiac arrest is when the heart suddenly and unexpectedly stops beating, leading to an immediate loss of consciousness, pulse, and breathing because blood flow to the brain and body ceases. It is a medical emergency that requires immediate treatment with CPR and, if available, an AED, to have a chance of survival. The most common cause is an electrical malfunction in the heart, often triggered by an abnormal heart rhythm (arrhythmia).

A cardiac device is a medical implant or external monitor that helps control or monitor the heart's rhythm and pumping function. Common types include pacemakers for slow heartbeats, implantable cardioverter-defibrillators (ICDs) to correct life-threatening fast rhythms, and cardiac resynchronization therapy (CRT) devices for heart failure. These devices are used to treat irregular heartbeats, manage heart failure symptoms, and prevent sudden cardiac death.

Angioplasty is a medical procedure that uses a balloon to open a blocked or narrowed artery, improving blood flow. A doctor guides a catheter with a deflated balloon to the site of the blockage, inflates the balloon to flatten plaque against the artery wall, and then deflates and removes it. A stent, a small mesh tube, is often placed during the procedure to help keep the artery open.

Angioplasty is a minimally invasive procedure to open narrowed or blocked arteries, commonly the coronary arteries in the heart, to improve blood flow. It involves threading a catheter with a balloon to the blockage, inflating it to press the plaque against the artery walls, and often placing a stent (a small metal mesh tube) to keep the artery open. The procedure can also be used for other arteries, such as those in the legs or neck.

A coronary angiogram is an X-ray procedure that uses a contrast dye to visualize blockages or narrowing in the heart's blood vessels. During the procedure, a thin tube called a catheter is inserted into an artery in the groin or arm and guided to the heart, where dye is injected to make the arteries visible on X-rays. It is used to diagnose conditions like coronary artery disease and to help plan treatments.

A leadless pacemaker is a tiny, self-contained device that is implanted directly into the heart to regulate a slow heartbeat, eliminating the need for wires and a chest-wall pocket. It is delivered via a catheter inserted through a vein, often through the femoral vein, and is a less invasive alternative to traditional pacemakers for some patients. These devices offer advantages such as a lower risk of infection, compatibility with MRI scans, and a shorter procedure time.

RDN therapy, or renal denervation, is a minimally invasive procedure for treating resistant high blood pressure (hypertension) that doesn't respond to other treatments. It involves using a catheter to send radiofrequency or ultrasound energy to burn the sympathetic nerves along the renal arteries, which reduces nerve activity and helps lower blood pressure. The procedure is intended for patients who have high blood pressure despite taking multiple medications or who have side effects from them.

An AICD doctor is a cardiologist, specifically an interventional cardiologist or cardiac electrophysiologist, who specializes in implanting Automatic Implantable Cardioverter-Defibrillators (AICDs). These doctors are qualified to perform the procedure to insert the device, which is used to treat life-threatening irregular heartbeats like ventricular fibrillation by delivering an electrical shock to restore a normal heart rhythm.

A chronic total occlusion (CTO) is a complete blockage in a coronary artery lasting at least three months, leading to reduced blood flow to the heart. While it can cause chest pain and shortness of breath, some people may have no symptoms as the body can develop collateral blood vessels to bypass the blockage. Treatment options include medication, and for persistent symptoms, percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) surgery.

Calcium management involves a complex system of hormonal regulation, mainly involving parathyroid hormone (PTH), vitamin D, and calcitonin, to maintain blood levels. For individuals with specific conditions, management also includes adjusting dietary intake and using supplements like oral calcium, vitamin D, or even synthetic PTH. In severe cases of low calcium, treatment may require intravenous (IV) calcium gluconate.