Sunday, June 26, 2011

Relax Your Heart

Based on a talk given at C. Purser MD’s wellness group, Bradenton, FL on June 23, 2011

The human heart is an amazing organ. It is small, about the size of one’s fist. It starts beating well before birth and in fact even before brain waves are detected in the fetus. An adult human heart beats over 100,000 times a daily pumping about 2000 gallons of blood daily. It supplies freshly oxygenated blood that traverses a vast network of blood vessels that may stretch approximately 60, 000 miles in an average adult.

It is a self contained metabolic powerhouse. It has the ability to generate its own electricity. With each squeeze of the heart muscle pump, blood is ejected form the heart generating the systolic blood pressure. Following every heart beat that results in the ejection of blood, there is a rest period which is very brief. In this short span of time, the cells that comprise the heart relax and get ready for the next heart beat. However, the heart does not completely relax. It maintains a lower blood pressure called the diastolic blood pressure. It is during this phase of relaxation, the three major blood vessels that supply the heart muscle, also called the coronary arteries, fill with blood.

The three main components of the heart are the electrical, mechanical and plumbing parts. Looking at how much the heart has to work day in and day out, the laws of probability are against the heart working one’s entire lifetime without something malfunctioning, even if one aims to maintain perfect health. Disturbances in the electrical component of the heart are manifested by either too slow or a rapid heart beat. Weakening of the heart muscle pump most commonly results from blockages in one or more of the three major blood vessels supplying the heart muscle.

There are several conventional risk factors for heart disease that are well known. There include hypertension, high levels of blood lipids, diabetes, smoking, obesity and a family history. Several of these conventional risk factors may coexist in the form of the metabolic syndrome.

Many of these risk factors are also lifestyle related. When we talk of lifestyle, we generally refer to diet and exercise. Another contributing factor from modern living is stress. A stressful lifestyle seems ubiquitous in these times, at work, at home and even planning and taking a vacation can be stressful at times.

Cardiologists such as myself diagnose and treat problems related to the electrical, plumbing and mechanical parts of the heart. Physicians also address coexisting risk factors mentioned earlier and there are many medications available to optimize these risk factors.

When it comes to addressing underlying stress as a contributor to heart disease, there is usually not much talked about except to advise patients to minimize stress in their lives. As we all know, this is easier said than done. Stress comes in many forms. We are constantly battered by stressful situations. A house or a car which may be a source of joy and comfort today can be a source of stress tomorrow. Life is unpredictable, but our response to life and stress can be predictably positive if we understand the mechanism of the stress response and how it affects our body.

The headwaters of the river of stress that sometimes flows through us is sourced from what we see, hear and do. A common theme that underlies stress is negativity in thought as opposed to positive thought that is usually associated with a sense of happiness.

The food we eat is processed in the gut. Stressful situations are processed in our brains. The human brain is a very compact structure that is responsible for coordinating everything in the body. Although we sometimes feel the effects of stress all over our body, there is a specific entry point in the brain where mental stress enters the physical body. This part of the brain where mental stress meets the physical body is called the limbic system. The limbic system comprises a set of structures deep within our brain spread over both the left and right hemispheres. It consists of three main structures called the hypothalamus, the hippocampus and the amygdala.

The hypothalamus is a busy place where the task of regulating hunger, thirst, pleasure, satisfaction, anger and aggressive behavior takes place. It also controls and regulates physiologically important parameters such as blood pressure, heart rate and respiration. The hippocampus deals with memory. Events in the present that generate short-term memory are converted here into long-term memory. The amygdala deals with fear, anger and aggression. Mental stress is usually associated with fear, anger, aggression, changes in heart rate, blood pressure. In addition, we carry the burden of each stressful situation in our short and long-term memories of events past.

The mind is closely involved with the limbic system. Based on the emotional input from the mind, the hypothalamus generates an output in two forms. One is through nerve pathways and the other is through the secretion of hormones from the endocrine glands. The hypothalamus is connected to a part of the nervous system called the autonomic nervous system. Through the two arms of the autonomic nervous system, namely the sympathetic and the parasympathetic, the hypothalamus has an effect on the heart through its control of the blood pressure and heart rate.

The sympathetic nervous system is involved in the “fight or flight response”. When this part of the nervous system is active, the heart rate and blood pressure go up and the workload of the heart increases. Emotions such as anger manifest their effects on the heart through the sympathetic nervous system. When the heart works harder, the blood pressure increases. This exerts a greater force on the delicate inner lining of the blood vessels potentially resulting in strokes and heart attacks. This occurs due to increased shear forces that may disrupt cholesterol plaques or blockages that may have already formed in the lining of blood vessels. The other arm of the autonomic nervous system called the parasympathetic nervous system is involved in “rest and relaxation”. This part of the nervous system is more active when the mind is calm. It rests the body machinery and helps it recovers from the stresses of daily life. It is active in states of deep sleep.

Mental stress also affects hormonal secretion from the endocrine glands. Here is an example of how stress can alter endocrine function. In response to stress, the hyopothalamus secretes a chemical messenger called corticotropin releasing hormone. This acts on the master endocrine gland, called the pituitary gland. The pituitary gland in turn releases adrenocorticotropic hormone or ACTH which controls the release of the stress hormone cortisol from the adrenal glands. Some of the effects of cortisol include increased blood sugar, elevated blood pressure and decreased immune function. Every time you are encountered with a stressful situation, there is a potential to allow this cascade to affect every cell of the body, unless you stop it at the level of the mind.

The mind functions as a gatekeeper. The mind receives sensory input through the five senses and these sensory influences are converted into thought forms. A lot of these thoughts go from our conscious mind to the subconscious mind for storage without evoking much of a response in our conscious mind. Some of these thought forms however, “catch our attention” and linger in our conscious mind. Also, thoughts may also bubble up from the subconscious to our conscious mind sourced from stored memories of past events.

Generation of negative thoughts in our conscious mind is related to our attachments that we have formed. The main basis of this attachment is fear. Fear of losing something that we hold dear is a form of this attachment. Fear clouds our minds and creates a hook of attachment that grabs relevant thoughts that fuel this fire. Negative thought generates unhappiness and this manifests as stress. Stressful emotions feed into the limbic system. From here, the body is affected through chemical and nerve pathways. The physiological balance of the body is altered, ultimately leading to diseases of end organs such as the heart.

Positive thoughts are associated with a sense of happiness within. The mind is a vast ocean of thought. Sometimes it becomes difficult  to isolate and encourage thought forms that generate a positive response within ourselves. Controlling the mental gate is very difficult. Each day we allow millions of visitors in the form of thoughts to enter through the turnstiles of this mental gate. We let in both good and bad thoughts. To deal with all these different thoughts is a tough undertaking. Rather than waiting till the end of the day or the weekend to deal with stressful thoughts generated by your daily transactions with the world, it is better to deal with them as and when then come up. Just as the heart takes a moment to relax after every heart beat, if you maintain awareness of your mind every time a negative thought shows up, you can work on developing your own inner tools to help you discard stress inducing negativity before it percolates into your physical body.

Along with dispensing with negative thought, it is also important to develop positive thinking. This helps engage the mind in something productive. If not, a stagnant idle mind can slip back into negativity. The basic foundation of positive thinking is a calm mind. One way to calm the mind is to fall asleep as we often try to do whenever stress overwhelms us and we are unable to cope. From a practical standpoint, this is easier said than done. Stress robs you of sleep and this sleep deprivation in turns puts a physiological stress on the body and this cycle goes on and on. Some need chemical intervention in the form of medication, alcohol etc to help us break this cycle.

Another way to consciously calm the mind is to develop breath awareness. Controlling your breathing is a conscious tool that is readily available to all and can be practiced anywhere. Slow deep breathing has an immediate calming effect on the mind. A calm mind results in a calm pulse. The heart rate slows and this allows the heart to relax for a longer period of time in between every heart beat.

Breathing exercise:

Please sit with your backs as straight as possible. Take your awareness from head to toe looking for areas of tension in your physical bodies. The various muscle groups of the body are storehouses of this tension. It could be in the muscles of your head, shoulders, back, arms or legs.

Let’s take in a few slow and deep breaths while maintaining awareness of your physical body. With each breath that you take in imagine a wave of relaxation coursing through your body from head to toe. As you breathe out, send out tension and negativity out of your body. After several breaths, continue maintaining an awareness of an increasingly relaxed physical body.

Now, bring your attention to your breath and leave your awareness of the body. Keep your awareness on the incoming and outgoing breath. After a few minutes of this practice, ride along with an incoming breath and imagine traveling right into your brain. From the vantage point of the brain, imagine looking down and watching each incoming and outgoing breath.

Now imagine looking down at the left and right lungs filling up with air with incoming breath. Between the two lungs is the heart. As the lungs fill up with air, think of the heart getting cushioned by two bags of air. This incoming air is insulating the heart, slowing it down and helping it rest. Associate each incoming breath with rest and relaxation of the heart. Keep your attention on this thought for a few minutes and gradually open your eyes.