Your Heart Risk Factors and Diving -

Your Heart

Risk Factors and Diving

Article by Nancy Huntington-Grahn

February is recognized as American Heart month as the time in a 12-month calendar to raise awareness about heart disease, but also to promote heart health.

The heart explained

Your heart is the size of your ﬁst and does more physical work than any other muscle in your body! The heart is a hollow, muscular organ with four chambers and an equal number of valves. The two upper chambers are known as the atria (right and left), while the bottom two chambers are known as the ventricles (both right and left). The atria are responsible for receiving blood that is then returned from different parts of the body. The ventricles, or lower chambers pump blood back to all the tissues throughout the body.

Valves that separate the atria from the ventricles are called the atrioventricular valves. There are two AV valves: right- tricuspid, left-mitral. Valves at the ventricular outlets are called the semilunar valves. There are two semilunar valves: pulmonary and aortic.

Your heart also has an electrical system that transmits cardiac impulses to cause the heart to beat. A cardiac cycle comprises the events that take place in the heart in between successive heart beats. The events include opening and closing of valves, but also the contraction and relaxation of the heart chambers. A cardiac cycle can be divided into two phases: systole and diastole. Systole is when the ventricles contract and push blood into the arteries. The diastole phase is when the ventricles relax and receive blood from the atria.

Your heart rate is important to your heart’s function. This strong muscle is responsible for circulating oxygen and vital nutrient ﬁlled blood throughout the body. When the heart is not working properly, just about everything from head to toe can be affected.

When it comes to what can be considered a normal heart rate, imagine yourself on a dive. You don’t want to go too fast, certainly not too slow and not too erratic. As divers, we aim for that nice well-orchestrated pace.

So, how does one check a heart rate or pulse? At the wrist, press lightly with an index ﬁnger and middle ﬁnger of one hand on the opposite wrist just below the base of the thumb.

Count the number of beats in 15 seconds and multiply by 4. This number is your heart rate! A normal heart rate for most adults is 60 – 100 beats per minute (BPM).

Risk factors

It is well known that several health chronic conditions, personal lifestyle habits, age and sometimes family history can increase risk factors for heart disease. Examples of risk factors include, but are not limited to: hypertension, hyperlipidemia, obesity/inactivity, cigarette/vape smoking and excessive alcohol consumption. Research shows time and time again that heart disease may be decreased, even preventable in more than half of the time with proactive lifestyle changes.

Smoking is the most preventable risk factor. There are countless resources available around the world for those seeking support to achieve smoking cessation for good. If you smoke, quit. Not only does smoking cessation lower your risk of heart disease over time but think about how much less gas consumption you’ll use on a long, leisurely dive.

Hyperlipidemia, even with a family history of high cholesterol, one can improve lab results with small lifestyle changes. Most healthcare providers agree total cholesterol: aim for less than 200 mg/ dl. High density lipoproteins (HDL- the “good cholesterol) 60 mg/ dl or greater.

Low density lipoproteins (LDL- the “bad cholesterol) 100 mg or less. Triglycerides: less than 150 mg/ dl.

If you don’t know what your lipid panel numbers are, ask your healthcare provider to order a lipid proﬁle panel. It’s a proactive way to keep in check with what’s going on inside your body and a good indicator of overall health.

Hypertension: uncontrolled blood pressure is the most common risk factor for heart disease. The upper number (systolic) is the pressure in your arteries when the heart beats. The lower number (diastolic) is the pressure when your heart is at rest in between beats.

General recommendations in an otherwise healthy adult is to aim for 130/80 consistently or below for heart health. As divers, always ensure adequate hydration pre/post dive, while achieving optimal blood pressures.

Obesity/ Inactivity: Most healthcare providers are currently advising patients to participate in 150 minutes of “increased activity” per week. This equates to 30 minutes of activity, five days per week. Activity should include aerobic activity, like biking, swimming and/or brisk walking to work the large muscle groups as well as exercise the most important muscle, your heart!

Diving is a very physical activity, from carrying heavy gear, to swimming through a water column that is 800x denser than air. Knowing the heart’s basic structure and function, controlling risk factors within one’s reach and participating in a healthy lifestyle is a gift every diver can give to oneself. This is a gift that keeps giving to your overall well-being.

Fun Facts:

An average heart can pump 2000+ gallons of blood per day!

In general, ultrasound technology can detect beating of cardiac tissue typically around 5-6 weeks in a fetus!

Over a lifespan of an average 70-year-old, a human heart can beat over 2.5 billion times!

Cheers to your health and happy diving!

Nurse Nancy Huntington-Grahn is a quarterly contributor to SDI International offering a unique perspective on health, well-being and the underwater world.

3 replies

Miguel 'Cutbacks' Jeronimo says:
March 23, 2025 at 5:19 pm

Hello,
Everything that was said above it’s true, I can prove it for my own experience!!

In 2023, I suffered a heart attack because my right coronary artery was completely blocked. After an angioplasty and the placement of a stent, everything started to improve. The staircase I used to struggle to climb—I was now able to go up while talking at the same time (before, I could only speak 2 or 3 minutes after reaching the top!!! Take this as a sign/symptom that something is wrong with your heart).

About six months later, I was back in the water. During this time, I followed a strict diet, quit smoking, but after a few months, I started having a cigarette occasionally, then about 4 or 5 a day!! I didn’t believe that smoking could clog my arteries! Even after losing 28kg, doing a daily 5km walk with steep inclines (excellent for cardio and recommended by my cardiologist), I had to undergo another intervention. This time, there was no heart attack, just (!!!) angina (more or less in the same area where the second stent was placed), which could have been avoided if I had listened to my doctor!!

Quit once and for all because I’ve already had TWO chances, and I don’t want to push my luck!!

This time, since it was detected early, my recovery is already complete. Although my doctor said I could dive now, I will wait another 15 days for a stress test and a series of exams to be on the safe side!

Conclusion: Obesity, lack of daily exercise, and smoking really KILL YOU (my father-in-law wasn’t as lucky as I was and is no longer with us!! He was 45, and when I had my heart attack, I had just turned 40!!!!)

So please, do everything you can so that your loved ones don’t have to suffer!!
Reply
- Nancy Huntington-Grahn says:
  April 8, 2025 at 9:00 pm
  
  Miguel ,
  Wow ! Thank you for sharing your personal journey ! I’m so happy for you that you’ve made a 100% full recovery . Safe diving & cheers to your health !
  Reply
Miguel 'Cutbacks' Jeronimo says:
March 23, 2025 at 5:25 pm

So the LDL to the people with Coranary disease should be under 70mg and the regular hypertension 120/70, 130 it’s a begin of the problems if he going up!!
Reply