Editing Heart murmur (section)

=== Interventions that change murmur sounds ===
* [[Inhalation]] leads to an increase in intrathoracic negative pressure. This increases the capacity of [[pulmonary circulation]], thereby prolonging [[Ejection fraction|ejection]] time. This will affect the closure of the [[pulmonary valve]]. This finding is also called ''Carvallo's maneuver.'' This maneuver in studies had a [[sensitivity (tests)|sensitivity]] of 100% and a [[specificity (tests)|specificity]] of 80% to 88% in detecting murmurs originating in the right heart.<ref name="pmid2897627">{{cite journal |vauthors=Lembo N, Dell'Italia L, Crawford M, O'Rourke R |title=Bedside diagnosis of systolic murmurs |journal=N Engl J Med |volume=318 |issue=24 |pages=1572–8 |year=1988 |pmid=2897627 |doi=10.1056/NEJM198806163182404}}</ref><ref name="pmid6497192">{{cite journal |vauthors=Maisel A, Atwood J, Goldberger A |title=Hepatojugular reflux: useful in the bedside diagnosis of tricuspid regurgitation |journal=Ann Intern Med |volume=101 |issue=6 |pages=781–2 |year=1984 |pmid=6497192 |doi=10.7326/0003-4819-101-6-781}}</ref> Positive Carvallo's sign describes the increase in intensity of a tricuspid regurgitation murmur heard with inspiration.<ref>''Harrison's Internal Medicine'' 17th, chapter 5, "Disorders of the cardiovascular system," question 32, self assessment and board review</ref>
* Abrupt [[standing (position)|standing]]
* Squatting, by increasing [[afterload]] and increasing [[Preload (cardiology)|preload]]. Squatting leads to an increase in [[systemic vascular resistance]]. An increase in systemic vascular resistance results in an increase in afterload. With HOCM, an increase in afterload will hold the obstruction in a more open configuration. This will decrease the loudness of the murmur with HOCM.
* [[Handgrip maneuver]], by increasing afterload. Like squatting, this will decrease the loudness of the HOCM murmur.
* [[Valsalva maneuver]]. Valsalva maneuver has utility in detecting hypertrophic obstructive cardiomyopathy ([[HOCM]]). According to one study, it has a [[sensitivity (tests)|sensitivity]] of 65% and [[specificity (tests)|specificity]] of 96% in [[HOCM]].<ref name="pmid2897627"/> Valsalva maneuver, as well as standing, decrease venous return to the heart. As a result, this decreases left ventricular filling. With HOCM, the outflow obstruction increases with a decrease in preload. This will increase the loudness of the murmur with HOCM.<ref>''Harrison's Internal Medicine'' 17th, chapter 5, "Disorders of the cardiovascular system," question 86-87, self assessment and board review</ref>
* Post [[ectopic beat|ectopic]] potentiation
* Inhaled [[amyl nitrite]]. This is a vasodilator that diminishes systolic murmurs in left-to-right shunts in ventricular septal defects. It also reveals right-to left shunts in the setting of pulmonic stenosis and a ventricular septal defect.<ref>{{cite journal|last=Cumming|first=Gordon R.|title=Amyl Nitrite Induced Changes in Cardiac Shunts|journal=Br. Heart J.|year=1963|volume=25|issue=4|pages=521–531|pmid= 14047161|pmc=1018027|doi=10.1136/hrt.25.4.525}}</ref>
* [[Methoxamine]]
* Positioning of the patient. In the lateral decubitus position or lying on the left side. This will make murmurs in the [[mitral valve]] area more pronounced.