how does the size of the heart change under conditions of chronic high peripheral resistance?

Answer 1

While still in the elastic limit and Starling's law stands good, the heart will compensate by causing the myacardium (cardiac muscle cells ) to hypertrophy and this will be detected as an enlarged heart.

Once the elastic stage passes the limit and the muscles enter the plastic stage then the chambers (initially the left side) dilates ,thus increasing further the size of the heart . Heart failure then unsues.

Hope this answers your question.

Answer 2

Chronic High Peripheral Resistance means there is prolonged > 2weeks-3 months ongoing resistance to the blood flow in your systemic circulation. In order to overcome the high pressure in your arteries, the heart in turn will try to pump harder. In the end, the heart , as a compensatory mechanism, will either a) enlarges (hypertrophies) by 1) dilation of chambers 2) thickening of the left ventricular wall) or b) increasing the heart/pulse rate or cardiac rate (>100 beats/min). If this continues, the heart will grow in size and will appear Cardiomegaly in CXR and there will be an irregularity in heart ryhthm.

Answer 3

The left ventricle hypertrophies, meaning it enlarges. Think of lifting weights. When you lift weights, your muscle grows to be able to overcome the resistance you are putting against it. The heart is a muscle too. So when it has to work harder to pump blood into your general circulation, it gets bigger. This, over time can be problematic despite the fact that is a compensatory mechanism. If the muscle gets too big, it will not be able to stretch. And the amount of blood that is pumped out of the heart is directly correlated to the stretch of the muscle. It can lead to congestive heart failure if the peripheral resistance is not lowered.

Answer 4

The heart is a muscle. Chronic high peripheral resistance makes the heart pump harder and work harder to get the blood to where it needs to go. Just as if you were to lift weights every day for a long period of time, your muscles would grow and get larger. The heart is the same way. It has and increased workload, making it work harder and pump harder, resulting in a larger heart, termed: cardiomegaly!