Arterial Screening-CASPro Testing

One out of two people have some form of heart disease.  Every 34 seconds someone suffers a fatal heart attack. Knowing your personal risk profile for cardiovascular disease will allow you to take the proactive steps necessary to slow down or stop the progression of this leading killer.  The good news is that heart disease is a life style disease that can be prevented and reversed.  The science behind this reversal is a combination of cardio pulse wave detection and analysis and treatment.  The source of intense study that resulted in the awarding of the Nobel Prize in 1998 has resulted in this new detection methodology and treatment.  The Hearftul Wellness Centre has this technology.

We use a machine called the CASPro to determine blood pressure, arterial pulse wave and central aortic systolic pressure. The arterial pulse wave corresponds to a blood pressure change caused by the contraction of the heart.  When the heart contracts, it ejects a bolus of blood into the already pressurized aorta.  The pressure rises further so the vessel, being elastic, becomes locally distended and the blood in it is set into motion, resulting in a pressure wave propagating along the aorta and then the arteries.  The arterial pulse wave pressure may be reliably measured at the radial artery by applanation tonometry.

 The arterial pulse waveform has two components: the first is the forward traveling wave when the left ventricle contracts and the second is the reflected wave returning from the periphery.  Ideally, for a young person whose arterial tree is generally soft and compliant, the reflected wave coincides with the diastole phase of the cardiac cycle and augments perfusion of the coronary arteries.  The propagating speed of the pressure wave is significantly dependent on the stiffness of the arterial wall.  As a person ages, the arterial tree begins to stiffen. This increases the pulse wave velocity, causing the reflected wave to return faster and with a higher amplitude. This reflected wave eventually coincides with the systole phase, resulting in a prolonged systole and a corresponding reduction in coronary artery perfusion.  The heart now has to work harder but the supply of oxygen and nutrients is compromised.  For the elderly, the reflected wave may occur very close to the systolic peak, resulting in an augmented wave and further prolonging the systole.  The presence and amplitude of the reflected wave in the arterial pulse are reflected in the radial pulse waveform. Therefore, by performing pulse wave analysis, we can obtain useful information about a client’s cardiac health.

We also evaluate the central aortic systolic pressure (CASP). This is the blood pressure at the root of the aorta or the largest artery in the body, as the blood is being pumped out of the heart.  CASP has been shown to be an important factor in relation to strokes and cardiovascular events, more than the brachial pressure or commonly known as the pressure at the arm.  CASP is different and usually lower than the brachial pressure in normal people.  When we are young, below 40 years old, the difference between CASP and the brachial pressure can be significant (up to 30mmHg).  However, as we age, the aorta gets stiffer and the compliance reduces.  As a result, the CASP increases and comes much closer to the brachial pressure.  In persons with high blood pressure, the CASP can be abnormally high for their age, showing “pre-mature” stiffing of the aorta.  It has also been shown that certain class of drugs used in the treatment of high blood pressure can also have an adverse effect on the CASP, increasing it instead of reducing, as shown in the CAFÉ study. (B. Williams et al, Differential Impact of Blood Pressure-Lowering Drugs on Central Aortic Pressure and Clinical Outcomes: Principal Results of the Conduit Artery Function Evaluation (CAFÉ) study. Circulation 2006; 113; 1213-1225.)  Therefore it is important to show that treatment aimed at reducing the CASP is in fact reducing the risks of stroke and heart events.