Being & Becoming: A Williams Syndrome “Mom-oir” Part 4(b)
PART 4(b): MURMURS OF THE HEART
The heart is a homely lump of muscle roughly the size of a person’s fist. I imagine Brendan’s neonatal heart as about the size of a colossal black olive. In the earliest stages of embryonic development, three layers of germ cells form: the mesoderm, the endoderm, and the ectoderm. Of the three, “Cells of mesodermal origin are the most abundant in the human body, representing a great variety of cell types, including the musculoskeletal system (bone, cartilage and muscle), cardiovascular system (heart, blood and blood vessels), as well as the connective tissues found throughout our bodies.” *
The embryonic development of the heart loosely follows the organ’s evolutionary development. The first stage of what will become the baby’s heart is the formation of a tube of cells, similar to the heart of a fish. This primitive tubal structure develops in the middle of the mesoderm. Orchestrated by instructions from the genes on the embryo’s chromosomes, inherited via DNA from both parents, the cells grow, split, differentiate. The tube folds back on itself, narrowing at junctures to begin to define four chambers, two of which will become the aorta and the vena cava, the other two an atrium and a ventricle.
At this point in its development, sometime around the third or fourth week, it’s like a frog heart, with two chambers. And at this point, the rhythmic pulsation of a heartbeat leaps into action. By eight weeks, it will be a four-chambered human heart, contracting rhythmically, pumping fetal blood through an immature circulatory system.
The human heart was made to beat. Two highly specialized clumps of cardiac cells, the atrioventricular and sinoventricular nodes, give rise to the impulse. They are the heart’s organic pacemakers. Cardiac muscle fibers, by virtue of their molecular structure and their arrangement, guide the flow of electric impulses from the nodes through the heart’s conduction system. All that’s needed for this electrical generation process are certain nutrients — sodium, potassium, and calcium, ionized by suspension in fluid — and the presence of oxygen, all supplied by the mother’s blood. A lone cardiac muscle cell placed in a medium with these elements available can beat on its own. The community of cells, that together form the heart muscle in the average adult human being, propel five to seven quarts of blood through a network of vessels that, if laid end-to-end, could circle the earth at the Equator twice and then some. **
My stepson Ryan tells of his motocross days, of “pump-arm” — the agony in hand, arm and shoulder muscles after a twenty-minute race, from the constant throttling, clutching, and braking of his dirtbike. Those muscles weren’t constructed for such unrelenting use for more than a short period of time. The heart was. Add in some neuro-electrical instructions from the brainstem to regulate the tempo of the heartbeat, and you have an organ that’s a masterpiece of functional efficiency, built for long-term endurance, to beat for a lifetime, if all goes well.
All doesn’t always go well.
It’s eleven o’clock before Dr. B., the pediatric cardiologist, arrives. He’s younger than I expect, given his credentials and affiliation with one of the major teaching hospitals in the country. His demeanor is quiet, serious. With thick, sandy hair, tortoiseshell glasses, in his preppie khakis and plaid sports shirt, he would look boyish but for his tired, wizened expression.
I stand next to Charles, watching as the doctor reads the EKG, watching as he listens not only to Brendan’s heart, but to every pulse in his body. Charles is armored within his own thoughts, an impenetrable wall he’s had the ability to instantaneously erect as long as I’ve known him, some eighteen years.
While Dr. B continues his examination, Brendan squirms, occasionally bleats his opposition to being restrained. With exquisite gentleness, the doctor soothes him, and continues with his stethoscope. We stand by silently. Finally, he steps back.
“You can get him dressed now.”
I suck in a deep breath of air and hold it. It will be years before I look back and comment that it feels like I never released that breath, that I’m holding it still.
“I do hear some peripheral pulmonic stenosis,” he informs us. “But nothing terrible. Certainly not Niagara Falls.”
“What could Harry have heard?” The leap back from the brink of disaster is abrupt and feels miraculous.
“It may have been a floppy valve, a tricuspid insufficiency, possibly from the hypoglycemia. But it’s very faint now. It’s resolving.”
I don’t need to know the precise medical details at this moment. I just need to know one thing. “Will it come back?”
“There’s no reason to think that it should.” He seems, through his apparent fatigue, happy to be able to impart glad tidings to a pair of parents.
“So…” Questions I can’t even articulate crowd my head, but Dr. B seems to intuit the essence of them all.
“He seems fine. I’ll want to do a follow-up checkup, another EKG in a week or two. You can go home as soon as Harry signs him out.”
The initial relief upon realizing that something potentially terribly awry has been set right, comes in a rush. It feels like a shot of gratitude straight to my own heart. The bad news is not so bad, not bad at all, after all. I don’t realize at that moment that after the bold relief recedes, a shadowy residue of the earlier worst scenario will remain in a parallel universe of other possibilities somewhere, lurk like a dormant potential which can still, given the wrong set of circumstances, rear up and destroy.
The doctor gives us a card with his office number and instructions to call to set up the appointment. He shakes our hand, smiles.
“Thanks, Doc,” Charles says.
“My pleasure.” Dr. B picks up his bag, smiles again, and leaves. It’s after midnight.
I’m relieved that Harry’s left the hospital, that we’ll have one more night of the maternity ward cocoon. In the event anything else goes wrong, medical help is close by. The thought footnotes itself: it was close by this afternoon, too, and didn’t prevent — or maybe it did. I want to go home. I’m afraid to go home. After Charles leaves, I lie in bed awake all night, holding Brendan.
* Curr Opin Cell Biol. 2019 December ; 61: 110–116. doi:10.1016/j.ceb.2019.07.012.
** I am not a health professional, just a researching kind of mom. If I’ve misstated or misunderstood any medical or scientific details, I welcome comments and corrections.
