Cardiac catheterisation is an invasive procedure that makes it possible to assess the heart function from the inside.
Depending on examination aim, the catheter is inserted into the left or right compartment of the heart.
To examine the left compartment, the cannula is inserted into an artery (femoral or brachial) with the purpose:
- to measure of the pressure in the left side of the heart;
- to examine the aortal and mitral valves;
- to study blood flow parameters;
- to examine the septum and cavity of the left ventricle.
To study the right side, a catheter is inserted into a vein (femoral or ulnar), in order:
- to determine pulmonary artery pressure, pulmonary valve status;
- to evaluate the function of the right atrium and ventricle.
General indications for cardiac catheterization are:
- low informative value of other non-invasive tests;
- preparation for heart or lung transplantation;
- need to evaluate the effectiveness of previous surgical interventions;
- need to detect congenital and acquired defects and anomalies of coronary vessels and heart;
- necessity to determine the severity of ischemia in CHD;
- need to measure pulmonary hypertension.
Contraindications for a catheter procedure
All contraindications for cardiac catheterization are either temporary or relative. These include:
- Acute myocardial infarction.
- Acute renal failure.
- Electrolyte imbalance.
- High levels of cardiac glycosides in the blood.
- Gastrointestinal bleeding.
Caution is advised in children under 1 year of age and patients over 70 years of age if there are underlying medical conditions:
- Cerebral circulatory disorders.
- Congenital diabetes mellitus.
- Pulmonary and renal insufficiency.
Additional examinations are recommended prior to considering catheterization in children.
The course of the procedure
The heart catheter procedure is performed under X-ray and ECG monitoring. The patient is laid on the back, given local anesthesia and sedated. General anesthesia is needed only in a very few cases. An incision is made in the skin at the insertion point of the radiopaque tube, through which the catheter is inserted into the vascular cavity, and led towards the heart. Its movement is monitored by an X-ray device. During the examination, a contrast agent is injected to visualize the vessels and heart cavities. A series of images are taken.
In course of the entire procedure, vital signs (heart rate, respiration rate and blood pressure) are kept under control.
The patient will not feel any pain during the procedure, but may feel discomfort and nausea, and will be asked to cough to reduce this.
Second opinion proves: heart catheter is not always necessary
Heart catheters are very frequently used in German hospitals for the diagnosis and treatment of cardiovascular diseases. However, almost half of these interventions are not performed on an emergency basis, but to identify the cause of cardiac complaints. Still, there are alternative methods that are non-invasive, i.e., do not require penetration into the body, and therefore have lower complication risks. To prevent unnecessary exams, the German Institute for Quality and Efficiency in Health Care (IQWiG) proposes to legislate a right to a second opinion for the following elective procedures:
- implantation of defibrillators and pacemakers;
- electrophysiological study with ablation;
- myocardial perfusion imaging;
- percutaneous coronary intervention;
- cardiac catheter study/coronary angiography;
- surgery for (intact) aortic aneurysms;
- heart valve replacement and aortocoronary bypass surgery.
If a heart attack is suspected a catheter is the only method
A catheter (thin tube) is inserted into a vessel through a small incision and moved from the groin or wrist to the heart. It can be used to detect narrowings in the coronary arteries and, if necessary, treat them with a stent. In Germany this procedure is performed more than a million times a year - approximately twice as often as in countries with comparable levels of health care.
In emergency situations when a heart attack may occur, invasive catheter examinations have no alternative and can be life-saving: if a patient complains of chest pain or breathlessness, or if there are certain risk factors, the heart should probably be treated immediately with a catheter.
Not all heart exams are appropriate
A second opinion may suggest alternative ways
If patients have doubts, healthcare professionals should encourage them to get a second opinion. It is important that patients feel confident before surgery, feel that they are well looked after, and understand why, when and what needs to happen. However, many patients hesitate to ask for a second opinion for fear of offending the attending physician. Therefore, a trusting relationship between patients and treating physicians is very important. It is also important to discuss all issues in detail in order to make a joint decision for or against the intervention.