J Thromb Thrombolysis (2015) 39:241–244 DOI 10.1007/s11239-014-1111-4
Calcific embolization with infective endocarditis involving the posterior mitral leaflet in a patient with underlying hypertrophic obstructive cardiomyopathy Navneet Lather • Kyle Niziolek • Peter Toth David M. Harris
•
Published online: 17 July 2014 Ó Springer Science+Business Media New York 2014
Abstract We report a case of infective endocarditis (IE) involving the posterior mitral leaflet (PML) with calcific embolization in a patient with hypertrophic obstructive cardiomyopathy (HOCM). Amongst HOCM patients with IE, the anterior mitral leaflet and basal septal myocardium are almost always involved due to the endocardial damage caused by recurrent outflow obstruction and valvular regurgitation. The management of our patient was complicated by moderate mitral stenosis, repeated calcific embolic strokes, dynamic left ventricular outflow track obstruction, and respiratory failure due to flash pulmonary edema. To our knowledge, this is the first reported case of PML involvement in HOCM presenting in this manner. Keywords Infective endocarditis Posterior mitral leaflet Calcific embolus Hypertrophic obstructive cardiomyopathy
Case report A 62 year old African American woman with history of hypertension, concentric left ventricular hypertrophy (LVH) with left ventricular outflow track (LVOT) obstruction, hyperlipidemia and active smoking presented to the Emergency Department (ED) with two days of productive cough, fever, headache, watery diarrhea and back pain. Her family also reported that she had been confused. Her family history was notable for a son
N. Lather (&) K. Niziolek P. Toth D. M. Harris Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA e-mail: [email protected]
diagnosed with HOCM who underwent implantable cardioverter–defibrillator placement for primary prevention of sudden cardiac death. In the ED, she was febrile at 102.4 F, blood pressure 147/95 mmHg, heart rate 116 beats/min and respiratory rate 22/min. Pertinent exam revealed a harsh crescendo-decrescendo systolic murmur best heard at the apex and lower left sternal border. Her pulmonary examination was significant for mild expiratory wheezing in the bilateral lower lung fields with associated dullness to percussion and egophony. Laboratory tests showed leukocytosis with a 24 % bandemia and her blood cultures were positive for Streptococcus pneumonia. Erythrocyte sedimentation rate was elevated at 64. Chest X-ray showed bibasilar airspace disease with suggestion of infiltrate at right lower lung base. Electrocardiogram (EKG) showed sinus tachycardia at116 beats/min with right-bundlebranch-block and LVH. Troponin-I level was elevated to 0.88 ng/ml. Her initial head computed tomography (CT) showed no acute abnormality (Fig. 1a). The patient was given intravenous Ceftriaxone and Azithromycin and admitted to the Medicine service for community acquired pneumonia. The cardiology service was consulted for evaluation of elevated troponin and severe LVH with associated LVOT obstruction, noted on a prior transthoracic echocardiogram TTE (Fig. 2a). In light of the patient’s sepsis, conservative management including treatment for the underlying infection and maintaining euvolemia was recommended. The leukocytosis continued to worsen despite appropriate treatment for Streptococcus pneumonia, based on the antibiotic sensitivity profile. Her confusion increased and a repeat head CT showed findings suspicious for new lacunar infarcts, which were confirmed by magnetic resonance imaging (MRI). TTE during current admission showed severely reduced LV cavity size, vigorous systolic function
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Fig. 1 a Initial head CT showing the absence of calcific embolization whereas (b) on repeat Head CT a calcific embolus is now appreciated in the posterior aspect of left frontal lobe
Fig. 2 TTE (a) done in 2009 and (b) done on current admission. The current TTE shows a mass attached to the PML (arrow) and increased calcifications with shadowing compared to previous study. There is also small pericardial effusion noted on (b)
with ejection fraction of 65–70 %, severe LVOT gradient of 49 mm of Hg, and a moderately to severely calcified posterior mitral leaflet (PML) with moderate mitral stenosis (MS). The mean gradient across mitral valve was 8 mm of Hg at heart rate 83 beats/min. There was systolic anterior motion (SAM) present with associated eccentric mildmoderate mitral regurgitation (MR) (Fig. 2b). Lumbar-spine MRI showed enhancement within L5-S1 vertebrae concerning for osteomyelitis. Cardiac MRI showed asymmetric hypertrophy of the left ventricle with a maximal thickness of 2.9 cm in the mid inferior septum suggestive of HOCM (Fig. 3). Unfortunately, she was unable to tolerate a complete cardiac MRI examination, due to claustrophobia, and the delayed gadolinium enhancement images were not performed. A subsequent fat pad biopsy was negative for amyloidosis. Twelve days into the hospital course, she developed tachycardia, hypertension, and increased respiratory distress with flash pulmonary edema requiring intubation and transfer to the cardiovascular intensive care unit. She was noted to have visual changes and a repeat head CT was obtained which showed a calcific embolus in the posterior aspect of left frontal lobe (Fig. 1b). This was not present on previous
123
Fig. 3 MRI. SSFP four chamber cine image demonstrates thickened infero-septum measuring 2.9 cm and calcified PML (arrows)
head CT scans. Transesophageal echocardiogram (TEE) showed severely calcified PML with highly mobile calcified segments attached to the atrial surface of leaflet (Fig. 4). This was presumed to be the source of her embolic strokes. She was treated with hydration as well as betablockers. Disopyramide therapy was attempted in addition
PML in a patient with underlying HOCM
243
was transferred to Hospice and transitioned to comfort care. She passed away on hospital day twenty-six.
Discussion
Fig. 4 TEE demonstrating highly mobile calcified mass attached to PML
to beta blockers to enhance negative inotropy and reduce LVOT gradient. She did not tolerate disopyramide due to QTc prolongation on the EKG. She was successfully extubated. Right heart catheterization showed low cardiac index of 2.1 l/min/m2. Left ventricular end diastolic pressure was 22 mgHg and Pulmonary capillary wedge pressure was 32 mm of Hg with peak gradient of 10 mm of Hg. The left heart catheterization showed non obstructive coronary artery disease. The maximal LVOT gradient on pull back across aortic valve was 42 mm of Hg. She had a prohibitive surgical risk for valve surgery and surgical myomectomy by the cardiothoracic team due to anticipated prolonged cross clamp time and critical condition. It was deemed that her best option was heart transplant if she recovered and was able to achieve 6 months of smoking cessation. Right ventricular pacing was considered to reduce LVOT gradient but was not ideal with underlying sepsis whereas mitral balloon valvotomy with significantly PML calcification carried high embolic risk. Her management provided significant challenge with obstruction at mitral and LVOT level. Sepsis induced vasodilation required significant volume resuscitation to maintain euvolemia whereas tachycardia caused dynamic changes in LVOT gradient and MS. High cardiac output state required to combat sepsis was blunted with use of beta blockers required to help optimize filling and reduce gradients across mitral valve and LVOT. On hospital day seventeen, she again developed hypertension, tachycardia, and flash pulmonary edema requiring re-intubation. Attempts to extubate the patient were unsuccessful. She developed worsening acute kidney injury with anuria, shock liver, and lactic acidosis. She had further deterioration in mental status. After discussions with the family, she
Infective endocarditis (IE) in patients with HOCM is a rare complication and the literature on IE in HOCM is virtually confined to case reports. During the last 20 years, only 33 cases have been reported in the English language literature [1, 2]. The higher risk of IE may be due to damage of the mitral valve caused by the high velocity outflow jet and turbulence of blood flow during ejection. This turbulent jet causes venturi effect leading to the lift of the anterior mitral leaflet (AML) towards the septum causing septal contact during systole with dynamic outflow track obstruction. Eccentric MR, which is often present in patients with LVOT obstruction, has been postulated by some as a predisposing factor for IE [2, 3]. On literature review of pubmed and EBSCO host, our case is the first to show IE involvement of PML with associated calcification and embolization in HOCM. All other cases so far have shown involvement of AML and septal myocardium. We believe our patient developed repeated episodes of IE since her TTE 4 years prior. This was likely related to her eccentric MR jet associated with HOCM causing damage to the posterior leaflet. On this admission her PML was significantly calcified and had an associated calcified highly mobile mass compared to prior TTE. The fragments from this calcified mass were likely the source for her embolic stroke. Additionally, her blood cultures were positive for Streptococcus pneumonia. This suggested subacute presentation of IE with bacteremia leading to vertebral osteomyelitis. In the literature on HOCM and IE the predominant microbial causal agents reported are staphylococci and streptococci [2, 3]. There are cases reported with IE involving mitral annular calcification and systemic embolization but none reported IE involving PML calcification leading to systemic manifestation as in our patient [4, 5]. A study conducted by Eicher et al. [6] involving 62 cases of IE of the mitral valve followed over five years with TEE demonstrated 15 had vegetations originating from MAC, while 47 had classic leaflet IE. Perhaps the best explanation for calcific superinfection and bacteremia appears to be due to endothelial erosion and turbulence in proximity to calcified mass which serves as a nidus for infection [4]. IE in HOCM is almost always restricted to patients with LVOT obstruction and is more common in those with both LVOT obstruction and left atrial dilatation [2]. A dilated left atrial cavity may reflect more severe hemodynamic impairment, with a higher outflow gradient and higher
123
244
degree of MR [2]. Our patient had both the findings of LVOT obstruction with peak gradient of 49 mm of Hg and left atrial volume index of 38 ml/m2. In addition to HOCM and MR, MS contributed to enlargement of the left atrium in our patient. Clinical history and examination remains the mainstay of diagnosis. From an imaging perspective, TTE is an excellent initial diagnostic tool for assessment of IE and HOCM. TEE can be utilized to detect vegetations when suspicion remains high despite non diagnostic TTE. Cardiac MRI is integral to assessment of HOCM when TTE is inconclusive and can provide valuable information to aid the management of patients with suspected HOCM and valvular dysfunction related to IE [7]. Cardiac MRI imaging is indicated in patients with known HOCM when additional information that may have an impact on management or decision making regarding invasive management, such as magnitude and distribution of hypertrophy or anatomy of the mitral valve apparatus or papillary muscles, is not adequately defined with echocardiography [8]. Furthermore, late gadolinium enhancement on cardiac MRI is associated with adverse events in adults with HOCM [7–9]. Antibiotic therapy directed at the causative microbial agent is the mainstay of the treatment and surgery should be considered promptly whenever there is traditional indication such as significant hemodynamic compromise, emboli, persistent fever and abscess in patients with underlying IE [10]. Medical therapy of HOCM consists of beta blockers and calcium channel blockers. Patients with HOCM may also benefit from disopyramide which is a negative inotropic agent and may reduce the LVOT gradient. By virtue of its anti-arrhythmic properties, disopyramide may be of particular benefit in HOCM patients with atrial fibrillation [11]. Right ventricular pacing has shown conflicting data to reduce resting LVOT gradient [12]. Alcohol septal ablation can be tried for patients who are not surgical candidates but complication rate remains high in inexperienced hands and low volume centers. Surgery for HOCM is considered for patients with resting or provocable LVOT obstruction (with gradient C30 mmHg at rest or C50 mmHg during exercise) who have substantial symptoms that are refractory to optimal medical therapy [11]. Surgical procedure may consist of valve replacement or repair for IE, and some authors reported relief of outflow tract obstruction after mitral valve replacement which may be explained by the removal of SAM of the mitral valve [10]. Valve surgery combined with septal myectomy seems logical but requires great expertise and carries a higher operative mortality
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[13]. Routine antibiotic prophylaxis in patients with HOCM is not recommended anymore per ACC/AHA guidelines update 2008 unless there is prosthetic valve or evidence of prior IE [14].
References 1. Louahabi T, Drighil A, Habbal R, Azzouzi L (2006) Infective endocarditis complicating hypertrophic obstructive cardiomyopathy. Eur J Echocardiogr. 6:468–470 2. Spirito P, Rapezzi C, Bellone P et al (1999) Infective endocarditis in hypertrophic cardiomyopathy, prevalence, incidence, and indications for antibiotic prophylaxis. Circulation 99:2132–2137 3. Durack DT (1995) Prevention of infective endocarditis. N Engl J Med 332:38–44 4. Minardi G, Pino PG, Sordi M, Pavaci H et al (2009) Infective endocarditis on mitral annular calcification: a case report. Cases J 2:9072 5. Lin CS, Schwartz IS, Chapman I (1987) Calcification of the mitral annulus fibrosus with systemic embolization. A clinicopathologic study of 16 cases. Arch Pathol Lab Med 111(5):411–414 6. Eicher JC, De Nadai L, Soto FX, Falcon-Eicher S, Dobsa´k P, Zanetta G, Petit JM, Portier H, Louis P, Wolf JE (2004) Bacterial endocarditis complicating mitral annular calcification: a clinical and echocardiographic study. J Heart Valve Dis 13:217–227 7. Moreillon P, Que Y-A (2004) Infective endocarditis. Lancet 363:139e49 8. Chan AK, Somarouthu B, Ghoshhajra B (2014) Magnetic resonance imaging for hypertrophic cardiomyopathy update. Top Magn Reson Imaging 23(1):33–41. doi:10.1097/RMR.0000000000000010 9. Smith BM, Dorfman AL, Yu S, Russell MW, Agarwal PP, Mahani MG, Lu JC (2014) Clinical significance of late gadolinium enhancement in patients \20 years of age with hypertrophic cardiomyopathy. Am J Cardiol. doi:10.1016/j.amjcard.2013.12.034 10. McIntosh CL, Greenberg GJ, Maron BJ, Leon MB, Cannon RO 3rd, Clark RE (1989) Clinical and hemodynamic results after mitral valve replacement in patients with obstructive hypertrophic cardiomyopathy. Ann Thorac Surg 47(2):236e46 11. Fifer MA, Vlahakes GJ (2008) Management of symptoms in hypertrophic cardiomyopathy. Circulation 117:429–439 12. Topilski I, Sherez J, Keren G, Copperman I (2006) Long-term effects of dual-chamber pacing with periodic echocardiographic evaluation of optimal atrioventricular delay in patients with hypertrophic cardiomyopathy [50 years of age. Am J Cardiol 97:1769–1775 13. Heric B, Lytle BW, Miller DP, Rosenkranz ER, Lever HM, Cosgrove DM (1995) Surgical management of hypertrophic obstructive cardiomyopathy: early and late results. J Thorac Cardiovasc Surg 110:195e206 14. ACC/AHA (2008) Guideline update on valvular heart disease: focused update on infective endocarditis. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 52(8):676–685. doi:10.1016/j.jacc.2008.05.008
Calcific embolization with infective endocarditis involving the posterior mitral leaflet in a patient with underlying hypertrophic obstructive cardiomyopathy Navneet Lather • Kyle Niziolek • Peter Toth David M. Harris
•
Published online: 17 July 2014 Ó Springer Science+Business Media New York 2014
Abstract We report a case of infective endocarditis (IE) involving the posterior mitral leaflet (PML) with calcific embolization in a patient with hypertrophic obstructive cardiomyopathy (HOCM). Amongst HOCM patients with IE, the anterior mitral leaflet and basal septal myocardium are almost always involved due to the endocardial damage caused by recurrent outflow obstruction and valvular regurgitation. The management of our patient was complicated by moderate mitral stenosis, repeated calcific embolic strokes, dynamic left ventricular outflow track obstruction, and respiratory failure due to flash pulmonary edema. To our knowledge, this is the first reported case of PML involvement in HOCM presenting in this manner. Keywords Infective endocarditis Posterior mitral leaflet Calcific embolus Hypertrophic obstructive cardiomyopathy
Case report A 62 year old African American woman with history of hypertension, concentric left ventricular hypertrophy (LVH) with left ventricular outflow track (LVOT) obstruction, hyperlipidemia and active smoking presented to the Emergency Department (ED) with two days of productive cough, fever, headache, watery diarrhea and back pain. Her family also reported that she had been confused. Her family history was notable for a son
N. Lather (&) K. Niziolek P. Toth D. M. Harris Division of Cardiovascular Diseases, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA e-mail: [email protected]
diagnosed with HOCM who underwent implantable cardioverter–defibrillator placement for primary prevention of sudden cardiac death. In the ED, she was febrile at 102.4 F, blood pressure 147/95 mmHg, heart rate 116 beats/min and respiratory rate 22/min. Pertinent exam revealed a harsh crescendo-decrescendo systolic murmur best heard at the apex and lower left sternal border. Her pulmonary examination was significant for mild expiratory wheezing in the bilateral lower lung fields with associated dullness to percussion and egophony. Laboratory tests showed leukocytosis with a 24 % bandemia and her blood cultures were positive for Streptococcus pneumonia. Erythrocyte sedimentation rate was elevated at 64. Chest X-ray showed bibasilar airspace disease with suggestion of infiltrate at right lower lung base. Electrocardiogram (EKG) showed sinus tachycardia at116 beats/min with right-bundlebranch-block and LVH. Troponin-I level was elevated to 0.88 ng/ml. Her initial head computed tomography (CT) showed no acute abnormality (Fig. 1a). The patient was given intravenous Ceftriaxone and Azithromycin and admitted to the Medicine service for community acquired pneumonia. The cardiology service was consulted for evaluation of elevated troponin and severe LVH with associated LVOT obstruction, noted on a prior transthoracic echocardiogram TTE (Fig. 2a). In light of the patient’s sepsis, conservative management including treatment for the underlying infection and maintaining euvolemia was recommended. The leukocytosis continued to worsen despite appropriate treatment for Streptococcus pneumonia, based on the antibiotic sensitivity profile. Her confusion increased and a repeat head CT showed findings suspicious for new lacunar infarcts, which were confirmed by magnetic resonance imaging (MRI). TTE during current admission showed severely reduced LV cavity size, vigorous systolic function
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Fig. 1 a Initial head CT showing the absence of calcific embolization whereas (b) on repeat Head CT a calcific embolus is now appreciated in the posterior aspect of left frontal lobe
Fig. 2 TTE (a) done in 2009 and (b) done on current admission. The current TTE shows a mass attached to the PML (arrow) and increased calcifications with shadowing compared to previous study. There is also small pericardial effusion noted on (b)
with ejection fraction of 65–70 %, severe LVOT gradient of 49 mm of Hg, and a moderately to severely calcified posterior mitral leaflet (PML) with moderate mitral stenosis (MS). The mean gradient across mitral valve was 8 mm of Hg at heart rate 83 beats/min. There was systolic anterior motion (SAM) present with associated eccentric mildmoderate mitral regurgitation (MR) (Fig. 2b). Lumbar-spine MRI showed enhancement within L5-S1 vertebrae concerning for osteomyelitis. Cardiac MRI showed asymmetric hypertrophy of the left ventricle with a maximal thickness of 2.9 cm in the mid inferior septum suggestive of HOCM (Fig. 3). Unfortunately, she was unable to tolerate a complete cardiac MRI examination, due to claustrophobia, and the delayed gadolinium enhancement images were not performed. A subsequent fat pad biopsy was negative for amyloidosis. Twelve days into the hospital course, she developed tachycardia, hypertension, and increased respiratory distress with flash pulmonary edema requiring intubation and transfer to the cardiovascular intensive care unit. She was noted to have visual changes and a repeat head CT was obtained which showed a calcific embolus in the posterior aspect of left frontal lobe (Fig. 1b). This was not present on previous
123
Fig. 3 MRI. SSFP four chamber cine image demonstrates thickened infero-septum measuring 2.9 cm and calcified PML (arrows)
head CT scans. Transesophageal echocardiogram (TEE) showed severely calcified PML with highly mobile calcified segments attached to the atrial surface of leaflet (Fig. 4). This was presumed to be the source of her embolic strokes. She was treated with hydration as well as betablockers. Disopyramide therapy was attempted in addition
PML in a patient with underlying HOCM
243
was transferred to Hospice and transitioned to comfort care. She passed away on hospital day twenty-six.
Discussion
Fig. 4 TEE demonstrating highly mobile calcified mass attached to PML
to beta blockers to enhance negative inotropy and reduce LVOT gradient. She did not tolerate disopyramide due to QTc prolongation on the EKG. She was successfully extubated. Right heart catheterization showed low cardiac index of 2.1 l/min/m2. Left ventricular end diastolic pressure was 22 mgHg and Pulmonary capillary wedge pressure was 32 mm of Hg with peak gradient of 10 mm of Hg. The left heart catheterization showed non obstructive coronary artery disease. The maximal LVOT gradient on pull back across aortic valve was 42 mm of Hg. She had a prohibitive surgical risk for valve surgery and surgical myomectomy by the cardiothoracic team due to anticipated prolonged cross clamp time and critical condition. It was deemed that her best option was heart transplant if she recovered and was able to achieve 6 months of smoking cessation. Right ventricular pacing was considered to reduce LVOT gradient but was not ideal with underlying sepsis whereas mitral balloon valvotomy with significantly PML calcification carried high embolic risk. Her management provided significant challenge with obstruction at mitral and LVOT level. Sepsis induced vasodilation required significant volume resuscitation to maintain euvolemia whereas tachycardia caused dynamic changes in LVOT gradient and MS. High cardiac output state required to combat sepsis was blunted with use of beta blockers required to help optimize filling and reduce gradients across mitral valve and LVOT. On hospital day seventeen, she again developed hypertension, tachycardia, and flash pulmonary edema requiring re-intubation. Attempts to extubate the patient were unsuccessful. She developed worsening acute kidney injury with anuria, shock liver, and lactic acidosis. She had further deterioration in mental status. After discussions with the family, she
Infective endocarditis (IE) in patients with HOCM is a rare complication and the literature on IE in HOCM is virtually confined to case reports. During the last 20 years, only 33 cases have been reported in the English language literature [1, 2]. The higher risk of IE may be due to damage of the mitral valve caused by the high velocity outflow jet and turbulence of blood flow during ejection. This turbulent jet causes venturi effect leading to the lift of the anterior mitral leaflet (AML) towards the septum causing septal contact during systole with dynamic outflow track obstruction. Eccentric MR, which is often present in patients with LVOT obstruction, has been postulated by some as a predisposing factor for IE [2, 3]. On literature review of pubmed and EBSCO host, our case is the first to show IE involvement of PML with associated calcification and embolization in HOCM. All other cases so far have shown involvement of AML and septal myocardium. We believe our patient developed repeated episodes of IE since her TTE 4 years prior. This was likely related to her eccentric MR jet associated with HOCM causing damage to the posterior leaflet. On this admission her PML was significantly calcified and had an associated calcified highly mobile mass compared to prior TTE. The fragments from this calcified mass were likely the source for her embolic stroke. Additionally, her blood cultures were positive for Streptococcus pneumonia. This suggested subacute presentation of IE with bacteremia leading to vertebral osteomyelitis. In the literature on HOCM and IE the predominant microbial causal agents reported are staphylococci and streptococci [2, 3]. There are cases reported with IE involving mitral annular calcification and systemic embolization but none reported IE involving PML calcification leading to systemic manifestation as in our patient [4, 5]. A study conducted by Eicher et al. [6] involving 62 cases of IE of the mitral valve followed over five years with TEE demonstrated 15 had vegetations originating from MAC, while 47 had classic leaflet IE. Perhaps the best explanation for calcific superinfection and bacteremia appears to be due to endothelial erosion and turbulence in proximity to calcified mass which serves as a nidus for infection [4]. IE in HOCM is almost always restricted to patients with LVOT obstruction and is more common in those with both LVOT obstruction and left atrial dilatation [2]. A dilated left atrial cavity may reflect more severe hemodynamic impairment, with a higher outflow gradient and higher
123
244
degree of MR [2]. Our patient had both the findings of LVOT obstruction with peak gradient of 49 mm of Hg and left atrial volume index of 38 ml/m2. In addition to HOCM and MR, MS contributed to enlargement of the left atrium in our patient. Clinical history and examination remains the mainstay of diagnosis. From an imaging perspective, TTE is an excellent initial diagnostic tool for assessment of IE and HOCM. TEE can be utilized to detect vegetations when suspicion remains high despite non diagnostic TTE. Cardiac MRI is integral to assessment of HOCM when TTE is inconclusive and can provide valuable information to aid the management of patients with suspected HOCM and valvular dysfunction related to IE [7]. Cardiac MRI imaging is indicated in patients with known HOCM when additional information that may have an impact on management or decision making regarding invasive management, such as magnitude and distribution of hypertrophy or anatomy of the mitral valve apparatus or papillary muscles, is not adequately defined with echocardiography [8]. Furthermore, late gadolinium enhancement on cardiac MRI is associated with adverse events in adults with HOCM [7–9]. Antibiotic therapy directed at the causative microbial agent is the mainstay of the treatment and surgery should be considered promptly whenever there is traditional indication such as significant hemodynamic compromise, emboli, persistent fever and abscess in patients with underlying IE [10]. Medical therapy of HOCM consists of beta blockers and calcium channel blockers. Patients with HOCM may also benefit from disopyramide which is a negative inotropic agent and may reduce the LVOT gradient. By virtue of its anti-arrhythmic properties, disopyramide may be of particular benefit in HOCM patients with atrial fibrillation [11]. Right ventricular pacing has shown conflicting data to reduce resting LVOT gradient [12]. Alcohol septal ablation can be tried for patients who are not surgical candidates but complication rate remains high in inexperienced hands and low volume centers. Surgery for HOCM is considered for patients with resting or provocable LVOT obstruction (with gradient C30 mmHg at rest or C50 mmHg during exercise) who have substantial symptoms that are refractory to optimal medical therapy [11]. Surgical procedure may consist of valve replacement or repair for IE, and some authors reported relief of outflow tract obstruction after mitral valve replacement which may be explained by the removal of SAM of the mitral valve [10]. Valve surgery combined with septal myectomy seems logical but requires great expertise and carries a higher operative mortality
123
N. Lather et al.
[13]. Routine antibiotic prophylaxis in patients with HOCM is not recommended anymore per ACC/AHA guidelines update 2008 unless there is prosthetic valve or evidence of prior IE [14].
References 1. Louahabi T, Drighil A, Habbal R, Azzouzi L (2006) Infective endocarditis complicating hypertrophic obstructive cardiomyopathy. Eur J Echocardiogr. 6:468–470 2. Spirito P, Rapezzi C, Bellone P et al (1999) Infective endocarditis in hypertrophic cardiomyopathy, prevalence, incidence, and indications for antibiotic prophylaxis. Circulation 99:2132–2137 3. Durack DT (1995) Prevention of infective endocarditis. N Engl J Med 332:38–44 4. Minardi G, Pino PG, Sordi M, Pavaci H et al (2009) Infective endocarditis on mitral annular calcification: a case report. Cases J 2:9072 5. Lin CS, Schwartz IS, Chapman I (1987) Calcification of the mitral annulus fibrosus with systemic embolization. A clinicopathologic study of 16 cases. Arch Pathol Lab Med 111(5):411–414 6. Eicher JC, De Nadai L, Soto FX, Falcon-Eicher S, Dobsa´k P, Zanetta G, Petit JM, Portier H, Louis P, Wolf JE (2004) Bacterial endocarditis complicating mitral annular calcification: a clinical and echocardiographic study. J Heart Valve Dis 13:217–227 7. Moreillon P, Que Y-A (2004) Infective endocarditis. Lancet 363:139e49 8. Chan AK, Somarouthu B, Ghoshhajra B (2014) Magnetic resonance imaging for hypertrophic cardiomyopathy update. Top Magn Reson Imaging 23(1):33–41. doi:10.1097/RMR.0000000000000010 9. Smith BM, Dorfman AL, Yu S, Russell MW, Agarwal PP, Mahani MG, Lu JC (2014) Clinical significance of late gadolinium enhancement in patients \20 years of age with hypertrophic cardiomyopathy. Am J Cardiol. doi:10.1016/j.amjcard.2013.12.034 10. McIntosh CL, Greenberg GJ, Maron BJ, Leon MB, Cannon RO 3rd, Clark RE (1989) Clinical and hemodynamic results after mitral valve replacement in patients with obstructive hypertrophic cardiomyopathy. Ann Thorac Surg 47(2):236e46 11. Fifer MA, Vlahakes GJ (2008) Management of symptoms in hypertrophic cardiomyopathy. Circulation 117:429–439 12. Topilski I, Sherez J, Keren G, Copperman I (2006) Long-term effects of dual-chamber pacing with periodic echocardiographic evaluation of optimal atrioventricular delay in patients with hypertrophic cardiomyopathy [50 years of age. Am J Cardiol 97:1769–1775 13. Heric B, Lytle BW, Miller DP, Rosenkranz ER, Lever HM, Cosgrove DM (1995) Surgical management of hypertrophic obstructive cardiomyopathy: early and late results. J Thorac Cardiovasc Surg 110:195e206 14. ACC/AHA (2008) Guideline update on valvular heart disease: focused update on infective endocarditis. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 52(8):676–685. doi:10.1016/j.jacc.2008.05.008
