Thorax 2--Brief info about some cardiac techniques

Procedure of Balloon Angioplasty
• Alternative name: Percutaneous transluminal coronary angioplasty (PTCA)
• a non-surgical procedure that relieves narrowing and obstruction of the arteries to the muscle of the heart (coronary arteries).
• This allows more blood and oxygen to be delivered to the heart muscle.
• PTCA, is now referred to as percutaneous coronary intervention, or PCI, as this term includes the use of balloons, stents, and atherectomy devices.
• Percutaneous coronary intervention is accomplished with a small balloon catheter inserted into an artery in the groin or arm, and advanced to the narrowing in the coronary artery.
• The balloon is then inflated to enlarge the narrowing in the artery.
• When successful, percutaneous coronary intervention can relieve chest painof angina, improve the prognosis of individuals with unstable angina, and minimize or stop a heart attack without having the patient undergo open heart coronary artery bypass graft (CABG) surgery.
• high risk ( 10 times compared with a purely diagnostic catheterization)
• oral intake restricted after midnight on the evening prior to the procedure
• patient pretreated with aspirin to diminish platelet deposition on disrupted endothelium
• Angioplasty done from femoral approach


Pericardiocentesis
• usually done in an intensive care unit's procedure room or even at the bedside.
• A health care provider will put an IV into patients’ arm in case fluids or medicines need to be given through a vein.
• clean an area just below the breastbone and apply a local anesthetic.
• insert a needle and guide it into the pericardial sac.
• Echocardiography is used to help position the needle and monitor fluid drainage, although electrocardiographic leads may also be used to help with positioning.
• Once the needle has reached the correct area, it is removed and replaced with a catheter.
• Fluid drains through this catheter into containers.
• Usually, the pericardial catheter is left in place so draining may continue for several hours.
Cardioplegic Solutions
• The use of cardioplegia solution has substantially increased the safety of cardiac surgery.
• It protects the myocardium by inducing a rapid and complete diastolic arrest, minimizing myocardial energy requirements and preventing ischemic damage during the arrest phase, and minimizing or preventing reperfusion injury once coronary blood flow is restored.
• Chemical components added to the cardioplegia solution, such as potassium and glucose, are largely responsible for this protective effect.
• Basic characteristics of cardioplegia solutions include temperature, osmolarity, and pH.
• Crystalloid solution has traditionally been used as a vehicle for cardioplegia solution
• however, laboratory and clinical studies have demonstrated favorable effects of blood-based cardioplegia solution.
• Single-pass and recirculating delivery systems can be used to administer either crystalloid or blood cardioplegia solutions.
• Cardiopulmonary bypass is established.
• After aortic cross-clamping, cardioplegic solution was administered from aortic root.
• Because complete cardiac arrest was not rapidly achieved, the aortic root was incised.
• Three cusps of the aortic valve were sutured.
• The aorta was closed; cardioplegic solution was administered from the aortic root.
• Then, cardiac arrest was rapidly achieved.
• After distal anastomosis of quadruple bypass was completed, the suture of the cusps was removed.
• There was no exacerbation of AR due to this method compared to the preoperative state.

Further Reading:
http://www.patentstorm.us/patents/5820586/description.html

Pacemaker insertion
• The pacemaker consists of three parts:
• Generator
• Leads
• Electrodes


o During a temporary pacemaker insertion:
• Temporary pacemakers are usually performed while the patient is in the hospital for a related heart condition (e.g., following a heart attack).
• The procedure may take place in the patient’s hospital room or in a minor surgery room.
• After a local anesthetic and a sedative (if necessary) have been administered, a small tube (catheter) is inserted into the skin, usually in the chest, neck or groin area.
• Wires from the external pacemaker are then threaded through this tube and into the heart.
• The external pacemaker is either hung on an IV pole by the bedside, or pinned to the bed sheets.
• Patients should not touch the unit and should limit their activity while the temporary pacemaker is in use.

 Permanent pacemaker insertion is more invasive, and is considered minor surgery. It can be performed either as an inpatient or an outpatient procedure. Permanent pacemaker insertion takes places in a cardiac catheterization lab, electrophysiology lab, hospital operating room or outpatient surgical facility.

The patient is given a local anesthetic, at which time the patient’s heart rate and blood pressure are monitored for the duration of the procedure. The insertion site will be cleaned and shaved. Then one of two methods will be used, depending on where the pacemaker is to be inserted:
• If the pacemaker is to be inserted into the chest (an endocardial implantation), then a small incision is made in the chest wall just below the collarbone to create a small surgical pocket.
• The wires (leads) from the pacemaker are then passed through a vein in the upper chest and placed in the right atrium or right ventricle, with the visual guidance of x-rays.
• The lead is then attached to the inner surface of the heart chamber using small screws or tines.
• If there is more than one lead, then the process is repeated.
• The main body of the pacemaker is then inserted into the surgical pocket created under the collarbone.
• Following insertion, the skin is closed with sutures. The entire procedure takes about an hour.
• Occasionally, leads are placed on the outer surface of the heart in a process known as epicardial implantation (outside the heart).
• When this procedure is used, the surgeon opens the chest wall, the leads are placed onto the heart’s surface and the pacemaker is inserted under the skin of the upper abdomen.
• This alternative is only used when the veins are unsuitable for passing the wires through in order to reach the inner heart (due to, for example, some types of congenital heart disease or if the patient is a child).

Defibrillator Paddles
This website has video and brief info about defibrillator paddles:
http://www.proceduresconsult.com/medical-procedures/defibrillation-EM-procedure.aspx