Brief Answer:
yes can have normal b.p with lower cardiac output!

Detailed Answer:
Hi,
Firstly thanks for choosing health care magic for your query!

Before giving answer to your first question let me give you a brief idea about the term Cardiac output ,blood pressure and factors which decides and maintain it.

Cardiac output and blood pressure are two important measures of the health and function of the cardiovascular system.
Cardiac output is a measure of the amount of blood that is pumped out of the heart in one minute,it specifically refers to the amount of blood pumped out of the left ventricle as this is the ventricle that supplies blood to the muscles and organs of the body.
Cardiac output is made up of two components, heart rate (HR) and stroke volume (SV).
Heart rate (HR) refers to the number of times the heart beats every minute (bpm).
Stroke volume (SV) refers to the quantity of blood pumped out of the left ventricle with every heart beat. The exact volumes are not easily measured, so they are often estimated based on what we know about stroke volume and the factors that it affects such as blood pressure which we can measure.

The equation for cardiac output is:
Heart rate * Stroke volume=Cardiac output.

Now lets have a idea about Blood pressure ,
Blood pressure (BP) is a measure of the force being exerted on the walls of arteries as blood is pumped out of the heart.

A person’s BP is determined by the following three factors;

1. Cardiac output (as we have already discussed)

2. Blood viscosity (the thickness of the blood)

3. Total peripheral resistance ‘TPR’ (the resistance the blood encounters on its voyage within the blood vessels)

So even if a person has low cardiac output,blood vessels can narrow when stress hormones (e.g. cortisol) are released by the body causing the smooth muscle within the walls of the vessel to contract (vasoconstriction)Hence raising the total peripheral resistance, Overall maintaining the blood pressure to normal.

Hence yes one can have a normal blood pressure even when cardiac output is low.

Now lets come to second question, "lightheaded like I am not getting good blood flow to my head."As you said your 2d echo and stress test is normal, lets rule out cardiac cause.
There is a artery name Carotid artery ,The carotid arteries are major blood vessels in the neck that supply blood to the brain,Carotid artery disease, also called carotid artery stenosis, is the narrowing of the carotid arteries, usually caused by atherosclerosis, stenosis of carotid artery can cause dizziness, black outs ,light headedness and syncope.Hence i would suggest you a carotid artery doppler test to rule out the blockage of coronary artery.

Dizziness and lightheadedness can be because of the involvement of inner ear also,Labyrinthitis is an inner ear disorder. It occurs when a vestibular nerve, important to spatial navigation and balance control, becomes inflamed,Symptoms include dizziness, loss of balance,so i would advice you a check up Ear nose throat doctor for the same.
Hence for light headedness i would advice you,
Carotid doppler
MRI brain
E.N.T check up

During respiratory inspiration, the venous return(blood return to heart) increases because of a decrease in right atrial pressure and Vena cava compression. So when you take deep breath,blood from various porgans starts to flow towards you heart ,as most of the blood diverts towards your heart ,you may hyperventilate or feel light headed .

In case you have any more query i would be happy to help!

Thanks,
Dr Rishu Saxena
Cardiologist.

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Brief Answer:
Can be orthostatic hypotension also!

Detailed Answer:
Hi
Yes it can be orthostatic hypotension also,as it is related to change in postures.Orthostatic hypotension, also known as postural hypotension,occurs when a person's blood pressure falls when suddenly standing up from a lying or sitting position,it occurs predominantly by delayed constriction of the lower body blood vessels, which is normally required to maintain an adequate blood pressure when changing position to standing. . As a result, blood pools in the blood vessels of the legs for a longer period and less is returned to the heart, thereby leading to a reduced cardiac output.
autonomic neuropathy, decreased blood volume, and age-related blood vessel stiffness are the most common reason behind it.

I would again advice you,
Carotid doppler
MRI brain
E.N.T check up

once cleared from this side we can treat it like orthostatic hypotension.
Treatment of orthostatic hypotension includes- increase salt and water intake (to increase the blood volume), wearing compression stockings, and sometimes medication (fludrocortisone) .

Question 2- hot showers but they really exhaust me and I don't understand why because I just stand there?
When you take hot shower ,the temperature of your body increases , as the temperature increases the blood vessels underlying the skin get dilated(increased size) so that more blood can flow through periphery and more heat could be lost in form of sweating ,as the blood flow to the periphery increases, blood flow to other organs are compromised giving you a feeling of exhaustion and lightheadedness.

A thorough investigation is important to rule out the cause .

Advice,
Follow up with reports.

In case you need any other help i would be happy to answer.

Thanks,
Dr Rishu Saxena

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Brief Answer:
Decreased preload!

Detailed Answer:
Hi again,
On eating blood flow towards the stomach increases ,which again decreases the venous return causing symptoms ,Try to takr small regular meals!
on bending also the pooling of blood in periphery increases again causing decreased preload!

Thank you
Dr Rishu Saxena

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Brief Answer:
.

Detailed Answer:
Hi,
As told by you earlier your echo and tmt were normal,so stress echo would not be much helpful in your case .
Rather go for the investigations i suggested.
Yes as explained earlier it can be othostatic hypotension,decreased preload or blockage in carotid artery.
They will make you run on a tread mill then lay down back and will take pictures in stress echo.

Thank you!

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