Multiple Doppler Waves in Hypertrophic Cardiomyopathy

IMAGE DESCRIPTION Hypertrophic cardiomyopathy (HCM) is an inherited disorder having ventricular hypertrophy that cannot be explained by loading conditions. Hypertrophy characteristically involves the ventricular septum with dynamic left ventricular outflow tract (LVOT) obstruction, although hypertrophy can affect any part of the left ventricle (LV). Hypertrophy of the ventricular wall and papillary muscles can cause midventricular systolic obstruction and apical aneurysm formation. A hypertrophied ventricle also results in decreased diastolic relaxation and diminished compliance of the LV. All these morphological abnormalities produce several hemodynamic consequences reflected in abnormal systolic and diastolic flow abnormalities in continuous wave (CW) Doppler flow recordings by transthoracic echocardiography.[1] Here is an image of various flow abnormalities in three cases of HCM depicting its different pathophysiological and hemodynamic alterations. Figure 1a and b shows a patient with HCM and LVOT obstruction at rest [Video 1] with a peak systolic gradient of 66 mmHg. The patient has additional midventricular obstruction [Video 2], causing a late systolic gradient of 26 mmHg. An early diastolic flow signal in CW Doppler is also seen in addition [Figure 1b] with a peak gradient of 38 mmHg. Figure 1c in another patient also shows an early diastolic flow with a peak gradient of 12.9 mmHg in addition to LVOT gradient of 57.8 mmHg [Video 3]. Mid-ventricular obstruction in HCM occurs either isolated or combined with LVOT obstruction due to systolic obliteration of the mid cavity resulting from hypertrophied septum, ventricular wall, and papillary muscles.[2] The mechanism of an early diastolic wave is that blood trapped in the LV apex in systole due to mid-ventricular systolic obstruction flows toward the base during early diastole when the obstruction is relieved. Such flow signal indicates the presence of apical aneurysm and mandates further imaging, particularly a cardiac magnetic resonance imaging for a better delineation as an apical aneurysm, which is a poor prognostic marker and associated with sudden cardiac death.[3]Figure 1: Continuous wave Doppler recordings showing various systolic and diastolic flow abnormalities (arrows) in hypertrophic cardiomyopathy (HCM). (a) Mitral regurgitation (MR) jet (arrow 1) starting with isovolumic contraction with parabolic shape and left ventricular outflow tract (LVOT) obstruction (arrow 2) peaking in late systole with a dagger shape. (b) In the same patient, aligning the Doppler beam toward the mid-ventricle shows a mid-ventricular gradient (arrow 3) and an early diastolic gradient (arrow 4) in addition to MR and LVOT flow spectra. (c) In another patient prominent presystolic wave (arrow 5) is seen in addition to a late systolic LVOT and an early diastolic Doppler flow signal. (d) Diastolic MR (arrow 6) is present in addition to a systolic MR in a patient of HCM and significant diastolic dysfunction with the Doppler beam aligned across the mitral valve. 1: MR jet, 2: LVOT gradient, 3: Midventricular gradient, 4: Early diastolic gradient, 5: Presystolic flow, 6: Diastolic MR {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1","caption":"The apical view in a case of hypertrophic cardiomyopathy shown in Figure 1a shows turbulence in the left ventricular outflow tract by color flow imaging.","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_gqrpx6bb"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 2","caption":"Apical view in the same patient of hypertrophic cardiomyopathy corresponding to Figure 1b. Showing turbulence in left ventricular mid cavity by color flow imaging. Mid-cavity obstruction is caused by the apposition of hypertrophied septum, lateral wall, and hypertrophied papillary muscle. Mid cavity gradient is obtained by continuous wave Doppler in addition to an early diastolic gradient.","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_xs5bkz66"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 3","caption":"Apical view in a case of hypertrophic cardiomyopathy corresponding to Figure 1c. Mid-cavity systolic obstruction, an early diastolic flow is recorded by continuous wave Doppler.","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_1h7kguxs"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Two important parameters indicating significant diastolic dysfunction are also seen in the image. In Figure 1c and Video 3, a prominent presystolic wave is seen in LVOT CW Doppler, indicating a forceful atrial contraction in the face of diastolic dysfunction. Presystolic waves are known to be a well-validated marker of diastolic dysfunction.[4]Figure 1d and Video 4 shows the presence of diastolic mitral regurgitation (MR), indicating advanced diastolic dysfunction, which causes diastolic pressure in LV exceeding that of systole, producing a pressure gradient between LV and left atrium in diastole, resulting in a diastolic MR jet when CW Doppler beam is aligned through the mitral valve. Diastolic MR without conduction blocks is a marker of significant diastolic dysfunction and, therefore, contributes to symptoms in HCM.[5] {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 4","caption":"Apical view in a case of hypertrophic cardiomyopathy corresponding to Figure 1d. Showing severe left ventricle (LV) hypertrophy, a small LV cavity, and a dilated left atrium, indicating significant diastolic dysfunction causing diastolic mitral regurgitation [Figure 1d].","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_kwt3pvsc"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Authors’ contributions This manuscript has only one author who is responsible for the entire work. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.