This open access site was

       originated September 2006

       Updated December 2008

   

       

 

 Cultivating health . . . with compassion

a medical perspective to share advancements in women’s health

to help women ease thru their menstrual cycles, the menopausal transition

and nurture post-menopausal health.

 

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Heartbeats . . .

 

The first sound,

the lub of lub-dub is

the sound of the mitral and

tricuspid valves closing.

The second sound,

the dub is

the sound of

the aortic and

pulmonary valves closing.

 

A Premature Contraction

 

 

 

is when a single heartbeat

occurs earlier than normal

 

During the

menopausal transition

there is a

natural decrease in

ovarian estrogen production.

 

For some women

this reduction in

hormone production

is associated with an

increase in heart rate

and an increased frequency in

palpitations and non-threatening

arrhythmias, such as

premature ventricular contractions (PVCs). 

 

The

Atrioventricular Node 

is a group of

special conduction

fibers at the


base of the wall between

the right atrium and ventricle.

The atrioventricular node relays

the electrical impulses to

the ventricle to

initiate contraction.

 		 

 

 

 

Women

  have different

risk factors

for heart disease

than men

 

Women's Arteries

 are smaller

 

 Women have

smaller and stiffer

conduit arteries than men

even when adjusted for height,

weight, and arterial pressure.

This contributes to earlier return

of reflected arterial pulse waves,

widened pulse pressure,

and adverse effects on
heart muscle (myocardial)

oxygen supply & demand.

 

Source:
Estrogen and Different Aspects of

Vascular Diease in Women and Men
Carl J. Pepine, Wilmer W. Nichols MDs
Circulation 2006

 

 

An arrhythmia

is often described

 as a palpitation

or a fluttering sensation

in the chest.

A "racing" heart is another description.

 

For some types of arrhythmias,

a skipped beat

might be sensed because

the next beat produces

a more forceful contraction

and a thumping sensation

in the chest.

 		 

 
   

 

 

 

 

 

 

  Understanding 

                    Irregular Heart Beats

                    During The Menopausal Transition 

Valerian Root

is an inexpensive herbal supplemental that helps

suppress sympathetic over-stimulation.

Valepotriates are the primary component of valerian root.

Valepotriates calm the central nervous system.

For many women valerian root helps suppress

the symptom of menopausal heart palpitations.

 
  

 

During the menopausal transition many, many women experience heart palpitations. Such episodes are alarming, often occur suddenly, occur in clusters, can be as brief as a moment or last for fifteen minutes or longer. Palpitations tend to lessen over time as the body adjusts to diminished estrogen (estradiol) production.

 

Presented below:

are a few suggestions in regard to managing episodes of menopausal heart palpitations. This overview also relates information about palpitations and the role of estrogen in cardiovascular (blood vessel) and cardiac contractile function (heart beat).

 

While this information may seem unfamiliar or complex, it has been presented to confirm that the symptoms many women experience during the menopausal transition often have a physiological/biological origin.

 
 

The Role of Estrogen

in Cardio-vascular

and Cardiac Contractile Function

    Advances in women's cardiovascular health have provided insight into the significant role of estrogen in cardiovascular function. For example, estrogen effects cholesterol metabolism and disposition, increases plasma levels of high density lipoproteins HDL, inhibits peroxidation (decay) of low density lipoproteins LDL, inhibits the proliferation of smooth muscle cells in the arterial wall, stimulates vasodilation (widening), and suppresses the norepinephrine induced vasoconstrictor (tightening) response of coronary arteries.

 

    Keep in mind, it is the fluctuations in estrogen that mediate the physiologically effects in microvessels which contribute to hot flashes. During a hot flash tiny blood vessels close to the skin open wide (rapidly) allowing for more blood flow. This extra blood flow is what causes a sense of warmth during a hot flash. The sweat that occurs with the hot flash is the body's natural mechanism to cool down. A hot flash is a vascular event, for medical perspective to lessen hot flashes click here.

 

 

 

 

Calming

Heart Palpatations

 

 

during the menopausal transition

                        

Slow breathing at . .

 six breaths per minute increases baroreflex sensitivity and reduces sympathetic activity. Slow breathing at six breaths helps reduce or reset arterial baroreflex sensitivity. 

 

The baroreflex is one of

the most important cardiovascular control

mechanisms adjusting heart rate and sympathetic output

to the blood vessels on a beat to beat basis.

 

It is helpful to practice this breathing

technique when you are not having palpatations.

                          

 

In additon to the physiological effects in blood vessels, as noted above, estrogen also modulates sympathetic and para-sympathetic tone. The sympathetic and para-sympathetic components of the autonomic nervous system work in partnership to modulate the heart beat.

   The sympathetic nervous system SNS innervates the heart through the cardiac plexus (a network of nerves at the base of the heart). The primary neurotransmitter (chemical messenger) of the SNS is norepinephrine.

 

                              Norepinephrine increases heart rate and contractility force.

   The para-sympathetic nervous system PNS innervates the heart through the vagus nerve (the 10th cranial nerve). The primary neurotransmitter (chemical messenger) of the PNS is acetylcholine.

 

                             Acetylcholine slows the heart rate and atrioventricular conduction.

 

 

 

Estrogen helped balance . . .

 

Prior to menopause

estrogen helped balance sympathetic (excited) and parasympathetic (relaxed) tone.

 

During and after menopause diminished estrogen can result in sympathetic 

over-stimulation resulting in symptoms such as heart palpitations.

 

 

 

 

 

 

 

 

 

 

 

 

 

Before Menopause

Estrogen Helped Relax Arteries

 

 

 

 for post menopausal women dimished estrogen often causes 

 arteries to constrict (tighten)

 this contributes to 

the increase in

 high blood pressure

for women over age 50

 

The transport of calcium ions across the cell membrane causes vasoconstriction (tightening). Estrogen generates a calcium antagonist (blocking) effect on vascular smooth muscle cells and cardiac fibers.

 

Prior to menopause, estrogen  blocked calcium entry into the cells, contributing to vascular smooth muscle relaxation (vasodilation), and decreased myocardial force generation, decreased heart rate, and decreased conduction velocity within the heart, particularly at the atrioventricular node.

  

  

 

  

 

 Baroreceptor Reflex Sensitivity

 

Estrogen has also been demonstrated to increase the rate of choline reuptake into cholinergic terminals, potentiate the activity of of choline acetyltransferase, (increases acetylcholine) and increase the magnitude of the phenylephrine induced reflex bradycardia, resulting in an enhanced baroreceptor reflex sensitivity.

 

  In addition to being

a contributing mechanism for

the regulation of blood pressure,

the baroreceptor reflex is a powerful source

of vagal afferent input to

the central nervous system,

and one of the most important physiological mechanisms affecting

efferent cardiac vagal activity.

 

A loss of sensitivity

of the baroreceptor reflex is

one of the fundamental mechanisms

underlying the deficits found in

 parasympathetic cardiac control.


 

An afferent nerve

carries impulses toward

the central nervous system.


An efferent nerve

carries impulses away

from the central nervous system.

 

Sympathetic efferent nerves are

present throughout the atria

(especially in the SA node)

and ventricles, including

the conduction system

 of the heart.

 

 

 

Getting Serious 

About Improving HDL Cholesterol 

 

 

HDL cholesterol goal is 60 mg/dl

 

Menopause

and post menopausal

diminished ovarian estrogen production

causes a significant decrease in

HDL cholesterol (good cholesterol).

 

Low HDL cholesterol is the primary

risk factor for women regarding cardio-vascular disease.

 

For a medical perspective regarding

increasing HDL cholesterol levels

click here

 

 

 

 
 
 
 

 

Natural Estrogen Agonists Help Ease Symptoms During The Menopause Transition

The biological actions of estrogen (estradiol E2) are mediated by  estrogen receptor alpha and estrogen receptor beta. ERa and ERb are distributed in specific tissues such as breast, brain, bone, skin and urinary tissue. For many postmenopausal women diminished estrogen results in diminished bone density, dry and less elastic skin and  thinner vaginal and urogenital tissue.

 

Estrogen replacement  counteracts these physiological changes. In addition to blood vessels, estrogen receptors also influence cardiac conduction (heart beat). For example estrogen receptors are present on ventricular myocytes: the heart muscle cells of the ventricles: the bottom chambers of the heart.

 

In biology, an agonist binds to a receptor of a cell and triggers a response by the cell. An agonist often mimics the action of a naturally occuring substance. 17 beta estradiol, and the phytoestrogens red clover and genistein (a soy isoflavone) act as estrogen agonists.

 

17 beta estradiol is a natural estrogen agonist. 17 beta estradiol is prescription estrogen replacement and is often made of a natural soy base. This prescription estrogen replacement is available as an oral tablet or a transdermal (skin) patch, cream or gel. 17 beta estradiol  has the same binding affinity for estrogen receptor alpha and estrogen receptor beta in estrogen sensitive tissues. This is why prescription estrogen replacement alleviates a variety of menopausal symptoms.

 

 

  Natural Phyto-estrogens

Phytoestrogen dietary supplements such as red clover and genistein (a soy isoflavone) also modulate estrogen receptors. As such, 17beta estradiol, and phytoestrogens red clover and genistein help ease symptoms during the menopausal transition. The type of estrogen agonist selected often depends on the degree and nature of the symptoms and time frame of the transition: perimenopause, menopause or post menopausal.  

 

The blood vessel lining (endothelium), smooth muscle cells (tighten or relax arteries), certain neurons in the central (sympathetic nervous system) and peripheral nervous systems are selective to estrogen receptor beta. The phytoestrogen genistein is about 30-fold estrogen receptor B selective. This is why many, many women find relief from vasomotor symptoms like hot flashes with phytoestrogen dietary supplement isoflavone compounds such as: genistein and red clover.

 

    

   Natural Estrogen Replacement

 

There are considerable options for menopausal women regarding hormone replacement. However, it is helpful to keep in mind, hormone replacement (HRT) refers to estrogen and a progestin. Estrogen replacement (ERT) supplements only estrogen.

 

Conjugated equine estrogen and medroxyprogesterone acetate is synthetic hormone replacement (a man made chemical). Equine estrogens are mixtures of estrogens purified from the urine of pregnant mares and contains sulphate and glucouronide derivatives, and equine-specific estrogens such as equilin not normally found in humans.

 

17B estradiol is natural estrogen replacement derived from soy.

 

   The timing for initiation,

and the type and mode (oral or transdermal)

of estrogen replacement

effects cardiac and blood vessel mechanisms. 

 
 


                      A Bit More About Palpitations

 

 

 

 

        

    Palpitations are heartbeat sensations that feel like the heart is pounding or racing. Palpitations may be an increased awareness of your own heartbeat, or may be a feeling of skipped or stopped beats. The heart's rhythm may be normal or abnormal. Palpitations can be felt in the chest, back, throat, or neck.

   Some individuals have a sensation of heart pounding and actually have a normal pulse at the time that they have this feeling. This situation can be difficult to assess, since the individual is certain that something must be wrong, but the objective data shows normal function. This situation has been dubbed enhanced cardiac awareness.

   Once it has been established that there is no heart rhythm or blood pressure disturbance to account for the sensation, the episodes tend to improve and eventually lessen. Individuals with disabling symptoms are sometimes treated with beta-blockers, presuming perhaps that inappropriate catecholamine tone may be responsible. Catecholamines (norepinephrine) stimulate a sympathetic response.

   Abnormal heart rhythms and extra heartbeats can cause some episodes of palpitations. These include premature atrial and ventricular beats, and atrial and ventricular arrhythmias. Premature atrial and ventricular beats are usually followed by a pause, after which the heartbeat is more forceful. It is this latter beat that is responsible for the symptoms of palpitations. Due to the pause, there is a greater stroke volume and higher level of catecholamines resulting in the perception of a thump.

   In addition, many premature ventricular beats are dissociated with the activity of the atrium of the heart, leading to valvular regurgitation, and felt as a pulsation in the neck or an urge to cough. The occurrence of atrial or ventricular beats may increase during the premenstrual period, pregnancy, menopause or advancing age.

The above information about palpitations originated from:
www.womensheartfoundation.org

 

  
  
 

 

The following is a brief overview

of how the heart beat and rhythm is coordinated 

The Heart's Electrical System

   The heart’s rhythm is coordinated by its own electrical system. With each heartbeat, the electrical impulse begins at the sinus (or sinoatrial, SA) node, also called the heart’s natural pacemaker. The SA node is a cluster of specialized cells, located in the right atrium. The SA node produces the electrical impulses that set the rate and rhythm of the heartbeat. The impulse spreads through the walls of the right and left atria, causing them to contract, forcing blood into the ventricles.

   The impulse then reaches the atrioventricular (AV) node, which acts as an electrical bridge allowing impulses to travel from the atria to the ventricles. There is a short delay before the impulse travels on to the ventricles.

 

    From the AV node, the impulse travels through a pathway of fibers called the HIS-Purkinje network. This network sends the impulse into the ventricles and causes them to contract. The contraction forces blood out of the heart to the lungs and body.

The SA node then fires another impulse and the cycle begins again.

  
   

Of Additional Note

To Help Regulate Heart Beat (Cardiac Contractile Function)

. . . this is really helpful

 

The normal electrical activity in the heart is controlled by the movement of ions through specialized channels in the membranes of cardiac cells. There are six principal ion currents that contribute to the nodal and pacemaking cell action potential and ten that underlie the myocardial action potential. Changes in channel functioning, effect action potential repolarization and can lead to arrhythmias.

Epidemiological studies suggest a cellular mechanism through which Omega 3 fish oils (DHA/EPA) effect ion channels to reduce the risk of arrhythmia. In short, fish oils appear to help regulate ion channel functioning, and as such keep the heart beating rhythmically.

 

For more information about cardiovascular health and fish oils visit:


http://www.into-the-heart.com/the_benefits_of_fish_oils_on_cardiovascular_health/index.html


 

Information is provided for educational purposes to help individuals form an understanding of biological processes as they effect health. This information is not intended for medical diagnosis or treatment.

 

   

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