The normal adult heart beats almost as regularly as a metronome, between 60 and 100 beats per minute. I say ALMOST, because when you let your breath out, the VAGUS nerve slows the normal heart slightly.
This is called Sinus Arrhythmia; SINUS because the electrical signal for the heart to contract originates in the usual place, the SINUS NODE.
ARRYTHMIA refers to the irregularity of the beat. Normally, the sinus node originates the electrical impulse, automatically generating the rhythm. The impulse spreads in an organized fashion throughout the Atria causing them to contract and send the collected blood to the ventricles.
The AV node is then activated, and after a slight delay, to allow the ventricles to fill, the impulse spreads to the Ventricles, causing them to contract, The heart is designed to be most efficient above 50 beats per minute, and below about 120. The rate is higher in the young and athletic. Athletes often have an efficient resting pulse in the 40s.
The arrhythmias usually cause the heart to beat too FAST. The most common arrhythmia is ATRIAL FIBRILLATION. In this condition, the upper chambers, the Atria, do not beat in a coordinated manner. The sinus node no longer regularly originates the electrical impulse because the electrical activity is continuously traveling in a disorganized way throughout the upper chambers in a self-propagating manner.
This quivering of the Atria allows the blood to pool in an area called the Atrial Appendages. This stagnant, pooled blood tends to clot, particularly if there is inflammation already present in the heart from vessel damage, obesity, or simply old age.
These CLOTS may find their way into the systemic circulation, and cause a STROKE. Another symptom of Atrial fibrillation is related to the irregular beats, which creates the sensation of PALPITATIONS, which causes you to be AWARE of your heart beating, and can be disturbing.
ATRIAL FLUTTER, and SUPRAVENTRICULAR TACHYCARDIA are other Arrhythmias. Some conditions cause the heart rate to be too SLOW. SICK SINUS SYNDROME is when the sinus node, the PACEMAKER, becomes more and more disordered, sometimes causing the heart to slow excessively, and produce FAINTING, sometimes producing a rapid heart rate.
Heart block is where the signal from the atria don’t reach the ventricles properly, sometimes not at all. The unsignaled ventricles still beat, but more slowly by an intrinsic, “idioventricular” rhythm.
My own experiences with ATRIAL FIBRILLATION will illustrate the problem and it’s treatment. A RAPID HEART BEAT was my introduction into arrhythmias. The rate was 140, and the EKG showed ATRIAL FLUTTER.
My Doctor gave me some PROPAFENONE to attempt a “chemical conversion” but it didn’t work, and i was given a CARDIOVERSION in the ER. The Arrhythmia returned in the form of ATRIAL FIBRILLATION within a couple of weeks. Back to the ER, and another cardioversion.
I was given propafenone, but that didn’t hold me much longer. A RADIOFREQUENCY ABLATION, where the focal points of aberrant electrical activation were isolated kept me in SINUS RHYTHM for a couple of years.
When the Fibrillation returned, Propafenone worked for a while, after which another Ablation, more propafenone, bood level regulation of propafenone to peak at night ( I invariably started fibrillation at night) and so on. With periodic trips to the ER for Cardioversion, I got by for a Decade.
Finally, when regulating the Propafenone couldn’t hold me in Sinus Rhythm longer than a month, I gave up, let myself go on fibrillating, and started taking ELEQUIS to PREVENT EMBOLI AND STROKE. Back when I first started fibrillating I had 2 main reasons for wanting to return to sinus rhythm..
First, I wanted to avoid ANTICOAGULANTS, which initially meant WARFARIN, and regular blood checks. At least, when I finally resigned myself to Fibrillation, Eliquis was available.
The second reason was to avoid medications, including beta blockers,which would be necessary to keep my heart rate in the acceptable range, 80 or below. By the time I gave up on controlling the AF, my rate was in the 70s, going down into the 50s, even while fibrillating.
This good fortune may have been caused another mild heart aberration I had all along, a Partial BUNDLE BRANCH BLOCK, which slowed down the electrical signals to my ventricles. Sometimes you get lucky, and 2 “wrongs” sometimes DO make a “right”. But don’t count on it.
Keep yourself as healthy as possible. Atrial fibrillation is more common with obesity and heart disease. SLEEP APNEA is also a cause, and should be ruled out if you develop Atrial fibrillation. I had a Sleep study, which showed that I had Sleep Apnea, which will be a story i will tell later.
Humans have a high energy requirement. Like a sports car we need to be turbosupercharged. We need an entirely separate Pulmonary circulation to handle our great oxygen demand.
Fish can get by on a single heart and circulation. They are “cold-blooded” and have no elevation of temperature above that in the environment. The water buoys them up, and they don’t need to constantly fight gravity.
Birds, and by extension, therapod dinosaurs, need more efficiency, and have a separate pulmonary circulation, just like we do. They share with us a DOUBLE CIRCULATION, a 4-chambered heart, with 2 entirely separate circuits.
In my residency, I saw a lot of congenital heart disease. In the process of development, the very early human embryo has a single circulation, just like “early” vertebrates, like fish.
In the process of development, the Systemic and Pulmonary circulations divide the previously unitary system into 2 separate systems, by a continuous spiral of partitions, or “septae”.
Ontogeny recapitulates Phylogeny: Development recaps Evolution. If this process of separation fails to happen in a given child, Congenital Heart Disease is the result:
- IASD. Interatrial Septal Defect is failure to separate the Atria, the upper chambers of the heart;
- IVSD, Interventricular Septal Defect, is failure to separate the Ventricles, the lower chambers of the heart;
- AV Communis is both of the above, plus failure of Atria and Ventricles, the upper and lower chambers, to separate, giving one big inefficient chamber.
When you listen to the hearts of these children, there are prominent murmurs, or noises, which betray the presence of turbulence and inefficiency, the very thing that evolution “tried” to prevent.
In the normal Human Heart, the blood returns from it’s systemic circuit through the capillaries, depleted of oxygen, into the vena cava. It passes to the Right Atrium, through the tricuspid valves, to the right ventricle.
With the contraction of the heart, the blood goes through the pulmonary artery, into the pulmonary capillaries, into close contact with air-containing alveoli. The oxygen passes through the alveolar membrane into the capillary blood, which becomes red. The oxygenated blood then passes into the pulmonary veins and on into the left atrium, and the systemic circulation.
It is interesting, and essential that the systemic arteries contain red, oxygenated blood, and the Pulmonary artery contains blue, oxygen-depleted blood. The “tired” blood, returning from the body must be “pepped up” by passing through the pulmonary circuit, picking up oxygen in the process.
Similarly a clot, originating in a quiet vein, perhaps a dilated, or varicose vein, is pumped into the Pulmonary circuit, where it lodges in the tiny capillaries and produces a PULMONARY EMBOLISM.
The embolus clogs the pulmonary circuit, increasing resistance, raises the normally-low pulmonary artery pressure and produces PULMONARY HYPERTENSION, placing more load and strain on the Right Ventricle.
Pulmonary Hypertension is also caused by a variety of Lung, heart, inherited and kidney diseases, as well as by certain drugs, high altitude, and Obstructive Sleep Apnea.
Please check the Mayo Clinic discussion that follows.
On a Friday afternoon last summer, a patient, “Barb,” texted me: “Call me. I can’t breathe.” As a heart failure nurse serving rural patients, getting messages like Barb’s launches my adrenaline. I called her immediately.
A month earlier, I’d trained Barb to send daily vital signs via my clinic’s digital portal—blood pressure, weight, heart rate, and oxygen saturation.
Barb was suffering from a congestive heart failure exacerbation: her lungs were filling with fluid. If we didn’t remove it, she’d need to be hospitalized or worse.
Once I was sure she wasn’t in emergency distress, I called the clinic’s cardiologist for instructions. Then I phoned Barb’s pharmacy and ordered a new diuretic to add to her regimen—a water pill so powerful in its fluid off-loading effect that I’ve nicknamed it the Bellagio. Within two hours, Barb had taken the pill and begun to urinate out the fluid flooding her lungs. By the next morning, she was breathing comfortably.
Without access to a telehealth program, Barb would probably have gone to the emergency room, then to the intensive care unit for expensive intravenous medications.
In a first of its kind study, Cleveland Clinic researchers found Bluetooth-enabled pacemakers successfully transferred information to doctors 95% of the time through an app on the patient’s smartphone or tablet. In comparison, traditional bedside consoles were successful 77% of the time.
Your heart and your brain are your two most vital organs, and if you enjoy life, they should be a top priority. These amazing structures are tethered to life-giving support by your arteries, just as the new you was tethered by your ubilical cord.
Life is fragile, hanging by a thread, or an artery. over the span of your life, These arteries can become plugged by fatty deposits called plaques. A healthy life style-SLEEP, DIET and EXERCISE– could slow down or prevent this atherosclerosis.
But everybody should know about the symptoms of HEART ATTACK and STROKE (1) and how to respond if the arteries sustaining your heart or brain become blocked.
You should be familiar with the hospitals in your area. How close are they? What are their capabilities? Are they Class 1 for heart attacks and stroke? Do they have a CATH LAB?
SPEED is important. Within minutes of the BLOCKAGE of an ARTERY to your heart or brain, vital cells start to die. The goal is to remove the blockage as soon as possible. CALL 911 as soon as you have heart attack or stroke symptoms. Don’t be afraid of the ER because of Covid, since almost all now use TELEMEDICINE SCREENING to keep infected patients segregated.
Alas, for many people, such PREVENTATIVE MEDICINE requires too much SELF DISCIPLINE AND CONVICTION. America has an epidemic of OBESITY and an avalanche of tasty FAST FOODS provided by a CONSUMER SOCIETY that is ever-attentive to the latest fads and trends.
Atrial fibrillation is chaotic and irregular atrial arrhythmia, the prevalence of which increases progressively with age. It causes significant morbidity and death. Many patients are asymptomatic or have symptoms that are less specific for cardiac arrhythmias, such as mild dementia or silent strokes.
Gregory Lip, Price-Evans Chair of Cardiovascular Medicine, University of Liverpool, gives us an overview of the condition.
Health journalist Judy Foreman talks about her new book Exercise Is Medicine: How Physical Activity Boosts Health and Slows Aging
This is Scientific American’s Science Talk, posted on April 24th, 2020. I’m Steve Mirsky. And under our current, often locked-down situation, it’s still really important to try to get some exercise. Judy Foreman is the author of the new book Exercise is Medicine: How Physical Activity Boosts Health and Slows Aging. She’s a former nationally syndicated health columnist for the Boston Globe, LA times, Baltimore Sun and other places, and an author for the Oxford University Press. We spoke by phone.
This Podcast is worth listening to in full. It will introduce some of the upcoming themes of DWWR.
Exercise is one of the 4 pillars of health, thriving and longevity, along with Diet, Sleep, and Intellectual Stimulation. We look forward to highlighting and reveling in these subjects.
Judy Foreman’s thesis “ exercise is medicine” is true in many dimensions, including industries desire to capture the many beneficial biological effects of exercise in a pill; it requires effort to get off your duff, and you need to budget the time to work out.
My preference is WALKING and WATER EXERCISE. I make passing the time PLEASANT by listening to BBC “in our time”, recorded on a water-proof mp-3 player. EXERCISE is both VALUABLE and ENJOYABLE!