Can Heart Murmurs Related to Pelvic-Floor Straining Diminish with Treatment?
No—the murmur you describe is almost certainly a benign physiological flow murmur triggered by increased cardiac output during Valsalva-like straining, and while pelvic-floor biofeedback will eliminate the straining behavior and thus the trigger for the murmur, the murmur itself is not pathological and requires no cardiac-specific treatment.
Understanding the Mechanism
The scenario describes a murmur that appears only when the patient is "searching for rectal and bladder sensations"—a behavior that involves repetitive Valsalva-like straining and increased intra-abdominal pressure. This physiological context is key:
High blood flow rate through normal cardiac structures produces innocent systolic murmurs, particularly during increased cardiac output states such as pregnancy, thyrotoxicosis, anemia, or any condition that transiently elevates stroke volume 1.
Valsalva maneuvers and straining transiently alter venous return and cardiac output, which can unmask or intensify flow murmurs across normal semilunar valves 2, 1.
Most systolic heart murmurs in adults do not signify cardiac disease and are related to physiological increases in blood flow velocity 1.
Cardiac Evaluation: What Is Required
Before attributing the murmur to benign physiology, a focused cardiac assessment is mandatory:
Grade 1–2 midsystolic murmurs in asymptomatic patients with an otherwise normal cardiac examination do not require extensive workup, including echocardiography, particularly in younger individuals 3, 2.
Echocardiography is mandatory for any grade ≥3 midsystolic murmur, any diastolic component, holosystolic or late systolic murmurs, or when symptoms such as syncope, angina, heart failure, or dyspnea are present 3, 2, 1.
Diastolic murmurs virtually always represent pathological conditions and require immediate echocardiographic evaluation 3, 1.
Dynamic auscultation maneuvers (Valsalva, standing from squatting, handgrip) can help differentiate pathological causes such as hypertrophic cardiomyopathy or mitral valve prolapse from benign flow murmurs 2.
Clinical pitfall: Do not assume the murmur is benign without confirming it is systolic, grade 1–2, and occurs in the absence of symptoms, abnormal S2 splitting, ejection sounds, or other cardiac findings 3.
The Pelvic-Floor Connection
The patient's behavior—"searching for rectal and bladder sensations"—strongly suggests underlying pelvic-floor dysfunction, likely dyssynergic defecation:
Prolonged excessive straining with soft stools or inability to pass stool despite adequate propulsive forces is the hallmark of defecatory disorders 4.
The need for digital evacuation or manual perineal/vaginal pressure to facilitate stool passage is the single strongest clinical clue for dyssynergic defecation, with approximately 85% specificity 4.
The concurrent sensation of incomplete emptying of both bladder and bowel suggests common underlying pelvic-floor dyssynergia, as both systems share neuromuscular pathways 4.
Rectal distention significantly influences bladder filling sensations—when the rectum is full, bladder sensations are reported at smaller volumes, demonstrating viscero-visceral cross-sensitization 5.
Definitive Treatment: Biofeedback Therapy
Biofeedback therapy is the first-line definitive treatment for dyssynergic defecation, carrying a Grade A recommendation with 70–80% clinical success rates 4.
How Biofeedback Works
Biofeedback uses visual or auditory feedback to train patients to relax pelvic-floor muscles during straining, restoring normal recto-anal coordination and eliminating the need for prolonged Valsalva maneuvers 4.
The therapy addresses both motor dysfunction (paradoxical pelvic-floor contraction) and sensory impairment (elevated rectal sensory thresholds) through operant conditioning 4.
Typical protocol involves 4–6 sessions over 8–12 weeks with a trained pelvic-floor therapist 4.
Expected Outcomes
Successful biofeedback eliminates the pathological straining behavior that triggers the transient increase in cardiac output and the associated flow murmur 4.
Predictors of biofeedback success include lower baseline rectal sensory thresholds and absence of depression; elevated first-sensation thresholds and depression independently predict poorer response 4.
Approximately 76% of patients with refractory anorectal complaints achieve adequate symptom relief after completing biofeedback 4.
Diagnostic Algorithm Before Biofeedback
Before proceeding to biofeedback, confirm the diagnosis of dyssynergic defecation:
Digital rectal examination (DRE) should assess:
- Resting anal sphincter tone (high tone supports dyssynergia)
- Puborectalis contraction during squeeze
- Perineal descent during simulated evacuation
- Ability to "expel the finger" 4
Anorectal manometry combined with balloon-expulsion test is the essential first-line diagnostic work-up 4.
Laboratory evaluation requires only a complete blood count to exclude anemia as an alarm feature; routine metabolic panels are not indicated 4.
Colonoscopy is not indicated unless alarm features (rectal bleeding, anemia, unintentional weight loss, sudden onset) are present or age-appropriate cancer screening has not been performed 4.
Management Strategy
Immediate Symptomatic Relief (First 1–2 Weeks)
Discontinue all constipating medications (opioids, anticholinergics, calcium-channel blockers, iron supplements) 4.
Initiate polyethylene glycol approximately 17 g daily (osmotic laxative) to soften stools and reduce straining 4.
Add bisacodyl approximately 10 mg orally once daily (stimulant laxative) to promote regular bowel movements 4.
Encourage fluid intake of at least 1.5 L/day and advise toileting 30 minutes after meals to exploit the gastrocolic reflex 4.
Avoid high-dose fiber or bulk laxatives until adequate hydration is ensured, as they can worsen outlet obstruction 4.
Definitive Therapy
Refer to gastroenterology or a pelvic-floor specialist for anorectal manometry, balloon-expulsion testing, and biofeedback therapy 4.
Do not treat as irritable bowel syndrome or slow-transit constipation with fiber or prokinetics, because the primary problem is outlet obstruction 4.
Escalation if Biofeedback Fails
After 8–12 weeks of biofeedback, order a colonic transit study because approximately 30% of patients have combined dyssynergic defecation and slow-transit constipation 4.
If slow transit is confirmed, add prucalopride approximately 2 mg daily (prokinetic with strong evidence for slow-transit constipation) 4.
Refer to colorectal surgery when structural abnormalities (e.g., large rectocele, rectal prolapse) are identified on defecography 4.
Common Pitfalls to Avoid
Do not order routine colonoscopy in young patients without alarm features; however, rectal wall thickening on imaging mandates endoscopic evaluation 4.
Do not perform colonic transit studies before anorectal testing; up to one-third of patients have secondary slowing due to untreated dyssynergia 4.
Do not assume the murmur is pathological without confirming it meets criteria for echocardiography (grade ≥3, diastolic component, symptoms, or abnormal cardiac findings) 3, 2.
Do not proceed to surgical interventions without confirming normal anorectal function; unrecognized dyssynergia leads to disastrous surgical outcomes 4.