Outcomes and Radiographic Findings of Isolated Spontaneous Superior Mesenteric Artery Dissection.

OBJECTIVES: This study aimed to investigate the features, treatments, and prognosis of patients with symptomatic and asymptomatic isolated SMA dissection. METHODS: Data from 35 consecutive patients in whom isolated SMA dissection was diagnosed on computed tomography angiography (CTA) between 2004 and 2015 at two general hospitals in Japan, were collected retrospectively. Nineteen symptomatic patients were compared, and 16 asymptomatic patients with incidentally revealed SMA dissection were also compared. In addition, the vascular remodelling and outcomes during follow-up were evaluated. RESULTS: The patient characteristics in the symptomatic and incidental groups were comparable except for age; mean ages were 55.9 ± 13.9 and 65.3 ± 10.9 years, respectively. Most of the symptomatic patients were managed conservatively (including antiplatelet therapy, anticoagulants, blood pressure control, or bowel rest). In addition, one patient was initially treated by endovascular intervention because of intestinal ischaemia, and another was switched from conservative to surgical treatment. The in-hospital outcome was good with no mortality. In the incidental group, all 16 patients were observed as outpatients without additional treatment. Complete remodelling of the false lumen was observed in 31% of patients with follow-up CTA, and was associated with the presence of symptoms and the absence of false lumen with blood flow at diagnosis. Neither recurrent or new onset abdominal pain, intervention for SMA dissection, nor SMA related death was observed in either group during the follow-up period (750 ± 779 and 1200 ± 951 days). CONCLUSIONS: The characteristics of asymptomatic patients with incidentally revealed SMA dissection were comparable with those of symptomatic patients, except for age. During follow-up, factors favouring complete remodelling of false lumens were the presence of symptoms, and the absence of false lumen blood flow at diagnosis.

Primary cardiac angiosarcoma detected by magnetic resonance imaging but not by computed tomography.

A 51-year-old man with a primary angiosarcoma of the right atrium is reported. The angiosarcoma was not detected by transthoracic echocardiography or computed tomography, but magnetic resonance imaging and transesophageal echocardiography did show the tumor of the right atrial free wall. We performed a transvenous endomyocardial biopsy of the tumor under the guidance of transesophageal echocardiography and made the pathological diagnosis. This case demonstrates the advantage of magnetic resonance imaging and transesophageal echocardiography for tumor detection over transthoracic echocardiography and computed tomography and the usefulness of transesophageal echocardiography for guiding the right atrial endomyocardial biopsy procedure.

Effect of angiotensin-converting enzyme inhibition on sympathetic tone in patients with mild to moderate heart failure.

Sixteen patients with mild to moderate heart failure were examined to investigate whether sympathetic deactivation plays a role in the improvement in the failing heart by chronic angiotensin converting enzyme (ACE) inhibition. Measurements, including echocardiography, blood examinations, neurohumoral samplings (atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), norepinephrine), and spectral heart rate variability analysis by Holter electrocardiography, were carried out before and 6 months after the administration of lisinopril (5-10 mg/day). Quality of life assessment was accomplished by the Specific Activity Scale (SAS) questionnaire. Treatment with lisinopril for 6 months resulted in a significant reduction in systolic blood pressure. The left ventricular diastolic dimension significantly decreased and fractional shortening significantly increased on echocardiography. Of the 16 patients, 8 had improvement in their symptoms as measured by the SAS. Lisinopril did not significantly reduce the plasma norepinephrine concentration, but there was a significant reduction in the plasma ANP and BNP concentrations. In the heart rate power spectral analysis, total spectral power, high-frequency components and low/high frequency ratios did not change significantly with lisinopril. The mechanism by which ACE inhibitors improve mild to moderate heart failure is not by suppressing sympathetic activity.

[Coronary flow after successful angioplasty in patients with acute myocardial infarction: comparison between coronary flow reserve by nicorandil and papaverine].

In order to evaluate coronary flow response to 2 different vasodilators, nicorandil and papaverine, in patients with myocardial infarction, we measured coronary flow reserve using a Doppler guide wire in infarct-related and non infarct-related arteries. The study group consisted of 28 patients with first acute myocardial infarction 3 weeks after successful coronary angioplasty within 6 hr after symptom onset. Twelve patients with atypical chest pain served as the control group. Coronary flow reserve induced by intracoronary papaverine(12 mg) was lower in infarct-related arteries than in non infarct-related arteries, but there were no differences in coronary flow reserve induced by intracoronary nicorandil(1 mg) between infarct-related and non infarct-related arteries. Coronary flow reserve induced by nicorandil was lower than that by papaverine in non infarct-related arteries and the control group. However, there were no differences between coronary flow reserve induced by nicorandil and papaverine in infarct-related arteries. Vasodilatory response induced by nicorandil was relatively preserved in infarct-related arteries compared with papaverine. These results suggest that impairment of coronary microvascular response in infarct myocardium varies in the different sites acted on by different vasodilator agents.

Clinical characteristics of patients with fresh left ventricular thrombus.

The present study analyzed the clinical backgrounds of 9 patients with fresh left ventricular thrombus (LVT) detected by two-dimensional echocardiography during the past 5 years. Patients with acute myocardial infarction were excluded. Left ventricular systolic function was disturbed either diffusely or segmentally in all patients with a mean ejection fraction of 33%. In 7 patients, echocardiography was performed shortly after furosemide therapy for New York Heart Association class IV congestive heart failure; echocardiography was also performed just before treatment in 4 of the 7 patients and LVT was not detected in any of them. Two patients died of underlying disorders within 2 months of detection of the thrombus. However, the LVT disappeared in the other 7 patients without any thromboembolic episodes during the 6 months after starting anticoagulant therapy. As fresh LVT developed shortly after diuretic therapy in patients with severe congestive heart failure associated with left ventricular systolic dysfunction, concomitant anticoagulant therapy is recommended.

Decreased left ventricular filling pressure 8 months after corrective surgery in a 55-year-old man with tetralogy of Fallot: adaptation for increased preload.

A 55-year-old man with tetralogy of Fallot underwent corrective surgery. Left ventricular filling pressure increased markedly with increased left ventricular volume one month after surgery, then decreased over the next 7 months, presumably due to increased left ventricular compliance.

Two cases of hypertrophic cardiomyopathy with coronary vasospasm.

Chest pain in patients with hypertrophic cardiomyopathy seems to be caused by relative myocardial ischemia due to the left ventricular outflow pressure gradient and myocardial hypertrophy. However, in 2 cases of hypertrophic cardiomyopathy chest pain was associated with coronary vasospasm. Thus, chest pain in these cases was decreased not by a beta-blocker but by isosorbide dinitrate and a calcium antagonist. Because beta-blockers are commonly used for hypertrophic obstructive cardiomyopathy and chest pain may be aggravated by beta-blockers in patients with coronary vasospasm, a combination of beta-blocker, isosorbide dinitrate and calcium antagonist was necessary for this hypertrophic cardiomyopathy with variant angina.

Increased thrombin-antithrombin III complex during an episode of paroxysmal atrial fibrillation.

Thrombin-antithrombin III complex (TAT) is a marker of thrombin generation, indicating increased coagulability. To investigate whether paroxysmal atrial fibrillation (PAf) is associated with an increased coagulation system, we measured TAT within 24 h after the documentation of PAf in 50 patients with structurally normal hearts. The mean age of the study population was 62 years old. In 32 patients, PAf was documented during routine physical examinations, electrocardiograms or echocardiograms and in the remaining 18 patients, it was reproducibly documented on more than two Holter electrocardiograms. Group I consisted of 38 TAT data sets from 38 patients who did not receive anticoagulant therapy during PAf episodes. At least one week after starting anticoagulant therapy, TAT was measured again in ten patients in whom there was evidence of PAf on the day of measurement. In the remaining 12 patients, PAf occurred while the patients were receiving anticoagulation. Group II consisted of 22 TAT data sets from 22 patients who received anticoagulation during PAf episodes. The average TAT value was 5.8 ng/ml in group I, while it was 2.8 ng/ml in group II (P<0.0001). TAT was greater than 5 ng/ml in 15 of the 38 patients in group I, and in four of the 22 patients in group II. In 20 symptomatic patients, we measured TAT again when the patients maintained sinus rhythm under the same anticoagulant therapy; four patients were receiving and 16 patients were not receiving anticoagulation therapy. TAT decreased from 6.4 to 2.3 ng/ml on average when PAf disappeared and sinus rhythm was maintained (P=0.0009). Increase in the coagulation system occurred transiently during or shortly after PAf episodes in about 40% of PAf patients. As patients with prior anticoagulation had a relatively low TAT value, anticoagulant therapy might be useful in patients with PAf.

Polymorphic ventricular tachycardia in a patient with adrenal insufficiency and hypothyroidism.

We describe a 60-year-old patient with adrenal insufficiency and hypothyroidism who experienced syncope as a result of polymorphic ventricular tachycardia associated with long QT intervals. The deep inverted T waves and long QT intervals were normalized about 8 weeks after starting steroid replacement therapy. Although there have been some reports on electrocardiographic abnormality or polymorphic ventricular tachycardia in patients with adrenal insufficiency, the pathogenesis remains unknown. Hormonal disorders should be considered as a cause of polymorphic ventricular tachycardia associated with long QT intervals, even if plasma electrolyte levels are normal, because life-threatening arrhythmia is treatable by supplementation of the hormone that is lacking.

[Hypertrophic obstructive cardiomyopathy in an elderly patient manifesting as refractory congestive heart failure of acute onset: a case report].

An 84-year-old woman was admitted to our hospital because of left heart failure of acute onset. Transthoracic echocardiography showed diffuse hypertrophy of the normal sized hyperkinetic left ventricle and chordae-like fluttering echoes attached to the mitral valve with severe mitral regurgitation signals. Mosaic flow signals were seen at the left ventricular outflow tract, but the velocity could not be measured. Emergent transesophageal echocardiography detected no obvious mitral valve prolapse. Cardiac catheterization showed greater than 100 mmHg pressure gradient between the left ventricle and femoral artery. Pressures in the femoral artery and pulmonary capillary wedge changed reciprocally in the intensive care unit; a bisferient narrow pulse pressure of the femoral artery was associated with increased v wave of the pulmonary capillary wedge pressure, and a wide pulse pressure of the femoral artery with absent v wave of the pulmonary capillary wedge pressure. Pressure monitoring in the intensive care unit, catheterization laboratory and transesophageal echocardiography were useful to understand the pathophysiology of the patient.

[Clinical evaluation of cholesterol embolization syndrome after cardiac catheterization].

The clinical features and outcomes of patients with cholesterol embolization syndrome after cardiac catheterization were evaluated. Among 4,920 patients undergoing cardiac catheterization during 1991 to 1996, the symptoms, signs, laboratory data, treatment and prognosis of eight (6 males and 2 females, mean age 69 years old) were reviewed who were pathologically or clinically diagnosed as having cholesterol embolization syndrome. All patients had more than two coronary risk factors. Mobile plaque of the aortic arch was detected in all five patients who underwent transesophageal echocardiography. All patients had one or more precipitating factors, including coronary angiography, percutaneous transluminal coronary angioplasty, cardiovascular surgery and cardiopulmonary resuscitation. The first symptom was renal dysfunction in four patients, skin findings of purple toes in two, muscle pain in one and new onset of refractory hypertension in one. The time after the precipitating factor to the onset of symptoms was 32 +/- 9 days on average. Eosinophilia was found in all patients and six patients revealed eosinophilia before the onset of symptoms. Four patients showed skin findings of purple toes which progressed in three of the four patients even after anticoagulant therapy was discontinued. Epidural anesthesia was markedly effective for skin findings of purple toes in two of the three patients. Diagnosis of cholesterol embolization syndrome is difficult because patients show various symptoms and there is an interval between the precipitating factor and the onset of symptoms. However, the conditions of the patients deteriorate rapidly and the prognosis is generally poor without supportive therapy in the early stage. Our study demonstrated that eosinophilia might be an important clue to early detection of cholesterol embolization syndrome. Furthermore, epidural anesthesia is effective for skin findings of purple toes in patients with cholesterol embolization syndrome. In conclusion, cholesterol embolization syndrome should be detected in the early stage based on eosinophilia or clinical symptoms after cardiac catheterization, and supportive therapy started as soon as possible, including discontinuance of anticoagulant therapy, hemodialysis for renal dysfunction and epidural anesthesia for skin findings of purple toes.

Aortic regurgitation in a patient with primary antiphospholipid syndrome--a case report.

We present the case of a 39-year-old woman with aortic regurgitation that may have been induced by primary antiphospholipid syndrome. The patient had suffered recurrent miscarriages, thrombocytopenia, and deep-vein thrombosis for the previous 16 years, and had been diagnosed as having primary antiphospholipid syndrome 9 years previously because of a high titer of anticardiolipin antibody. She had been receiving medication for moderate hypertension for 7 years. The patient was admitted to Tenri Hospital because of heart failure, which was thought to be caused by moderate aortic regurgitation, moderate hypertension, and mild chronic renal failure. Echocardiography revealed thickened aortic and mitral valves. Primary antiphospholipid syndrome might have induced valve regurgitation as a result of valvular thickening.

Myocardial contractile efficiency and oxygen cost of contractility are preserved during transition from compensated hypertrophy to failure in rats with salt-sensitive hypertension.

In Dahl-Iwai rats, salt-sensitive hypertension causes concentric left ventricular hypertrophy (LVH) at the age of 11 weeks, which is followed by LV dilatation with global hypokinesis and pulmonary congestion, ie, LV failure (LVF), at 16 to 18 weeks of age. To address the question of whether the cardiac remodeling from LVH to LVF is associated with modulations of mechanoenergetic properties, we serially measured the LV pressure-volume area (PVA) and myocardial oxygen consumption (MVO2) in isolated, isovolumically contracting hearts from this animal model. The end-systolic pressure-volume relationships obtained by stepwise changes of the LV volume were fit into a binominal regression model, which provided a value of LV contractility (E(es)) and a volume intercept (V0). A slope (the reciprocal of the LV contractile efficiency) and a PVA-independent MVO2 were determined by a regression analysis of the MVO2-PVA relation. The procedure was repeated at different Ca2+ concentrations in perfusate to estimate the oxygen cost of contractility (dMVO2/dE(es)). The MVO2 was further evaluated during K+-induced cardiac arrest to delineate the basal metabolism, which was independent of the E-C coupling. During the transition from LVH to LVF, the E(es) was decreased by 50% (from 681 to 338 mm Hg x g x mL(-1), P<.001), which was associated with a substantial increase in V0 (from 0.002 to 0.07 mL, P<.01). These alterations in both the inotropic state and the ventricular shape were associated with a 45% decrease in the PVA-independent MVO2 (from 800 to 440 mL O2 x beat(-1) x g(-1), P<.01). Despite these marked changes between the two stages, both the LV contractile efficiency and the oxygen cost of contractility remained unchanged. The MVO2 during cardiac arrest also showed an equal level among the groups; hence, from LVH to LVF, the nonmechanical O2 consumption by the E-C coupling decreased in a manner parallel to the basal contractile state. We conclude that (1) in this animal model, the heart failure transition is associated with a marked decrease in myocardial contractility and with ventricular remodeling; (2) despite these changes, the efficiency of the chemomechanical conversion is highly preserved; and consequently, (3) the total energy consumption per unit of failing myocardium is diminished along with its reduced nonmechanical energy expenditure for E-C coupling. These mechanoenergetic properties might constitute an adaptive mechanism in the energy-starved condition of chronically diseased myocardium.

Increased expression of interleukin-1 beta and monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 in the hypertrophied and failing heart with pressure overload.

Studies on the effects of proinflammatory cytokines on the heart suggest that they play some roles in the pathogenesis of congestive heart failure (CHF). To determine the involvement of proinflammatory cytokine in cardiac hypertrophy and CHF induced by mechanical overload, we investigated the expression of interleukin (IL)-1 beta and monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein-1 (MCP-1) in the left ventricle (LV) of Dahl salt-sensitive (DS) rats that showed hypertrophy of the LV induced by hypertension and subsequently developed CHF. The IL-1 beta mRNA content in the LV of DS rats increased 3.9-fold when LV hypertrophy developed, and the increase reached 6.2-fold at the CHF stage compared with that of age-matched Dahl salt-resistant (DR) rats. The amount of IL-1 beta in the LV was positively correlated with the LV weight/body weight ratio. Most of the IL-1 beta immunoreactivity was localized in the endothelial cells and interstitial macrophages. The mRNA levels of MCAF in the LV increased 3.6-fold at 11 weeks and reached 4.8-fold at the CHF stage relative to the age-matched DR rats. MCAF protein was localized to the endothelial cells and interstitial macrophages. In DS rats, the number of interstitial macrophages increased diffusely throughout the LV. We suggest that increased chemokine expression, macrophage infiltration, and proinflammatory cytokine expression play some role in the pathogenesis of cardiac hypertrophy and failure induced by chronic mechanical overload.

Early changes in the functions of cardiac sarcoplasmic reticulum in volume-overloaded cardiac hypertrophy in rats.

By sequestering activator calcium, the sarcoplasmic reticulum (SR) plays the central role in the excitation-contraction (E-C) cycle of cardiac muscle. Hence, functional changes in the SR in diseased myocardium might critically determine its mechanical characteristics. Previously, we demonstrated that both Ca2+ release and uptake were increased in SR isolated from hearts showing compensatory left ventricular (LV) hypertrophy taken from pressure-overloaded rats. However, it has not been elucidated whether such alterations also occur in the volume-overloaded myocardium. Rats in which volume-overloaded hypertrophy had been induced by aortocaval shunt 12 weeks prior to the investigation were compared to sham-operated controls in terms of SR Ca2+ uptake and release, and density of Ca2+ releasing channels (ryanodine receptors, RyR). Isometric tension and intracellular Ca2+ transients were also measured using the bioluminescent Ca2+ indicator, aequorin, in isolated LV papillary muscles. The extent of hypertrophy was verified by measuring the ratio of biventricular weight to body weight. In vivo, the aortocaval shunt rats showed normal LV contractility and slightly depressed LV relaxation, indicating a compensatory (adaptive) stage of LV function. In contrast, Ca2+ release, uptake, and maximal number of [3H]-ryanodine binding sites were all significantly lower in aortocaval shunt rats than in controls. Both the Ca2+ transients and isometric relaxation of the isolated myocardium were significantly prolonged in aortocaval shunt rats, though their amplitudes were similar in the two groups. Thus, the volume-overloaded cardiac hypertrophy, even at its hemodynamically compensatory (adaptive) stage, (i) was accompanied by abnormal Ca2+ handling, as indicated by prolonged intracellular Ca2+ transients and isometric tension traces, (ii) seems to involve subcellular mechanisms related to decreases in SR Ca2+ release and uptake functions, as well as to a decrease in the number of RyR. Therefore, changes in the intracellular processes underlying cardiac E-C coupling, including SR function, precede the development of this type of heart disease.

Mechanisms of negative inotropic effects of class Ic antiarrhythmic agents: comparative study of the effects of flecainide and pilsicainide on intracellular calcium handling in dog ventricular myocardium.

We studied the subcellular mechanisms responsible for the negative inotropic effects of the two Ic drugs flecainide and pilsicainide. Aequorin luminescence (Ca2+i) and isometric tension were recorded simultaneously in isolated trabeculae from the dog ventricle. In isolated myocytes from the same ventricle, the slow inward current (ICa) was recorded. Both flecainide and pilsicainide decreased peak Ca2+i, peak tension, and peak ICa concentration dependently. Each effect with flecainide was more marked than that with pilsicainide; however, Ca2+i and ICa paralleled each other in changes in tension, and the tension-Ca2+i-ICa relationship showed the same curve for each drug. We conclude that the difference in negative inotropic effects of these class Ic drugs are primarily related to their effects on L-type Ca2+ channels and the subsequent decreases in the amount of Ca2+ released from the sarcoplasmic reticulum (SR) during each cardiac cycle. Therefore, their negative inotropic effects may not be directly correlated with the essential mechanisms responsible for their antiarrhythmic action.

L-methionine augments mammalian myocardial contraction by sensitizing the myofilament to Ca2+.

L-Methionine is an essential amino acid that has been reported to have a potent positive inotropic effect on the mammalian myocardium. We studied the mechanisms of the inotropic effect in ventricular myocardium from the rabbit. In the isolated coronary-perfused whole heart, L-methionine in a millimolar range exerted concentration-dependent positive inotropic effects on the isovolumic left ventricle, which were associated with negative lusitropic effects (prolonged time course of relaxation). The chronotropic state and the coronary perfusion pressure were not affected. These complex effects on the isolated whole heart were not blocked by pretreatment with (mumol/L) propranolol 1, prazosin 1, carbachol 3, staurosporine 1, or [Ser1,Ile8]angiotensin II 0.1. To further study the subcellular mechanisms, isolated ventricular papillary muscles from the same species were loaded with a bioluminescent indicator, aequorin, to monitor [Ca2+]i. In the presence of 3 mmol/L L-methionine, the isometric tension showed a similar combination of the positive inotropic and negative lusitropic effects as observed in the whole heart. In contrast, the simultaneously recorded intracellular Ca2+ signals did not increase in amplitude but instead decreased. The [Ca2+]i-tension relation shifted to the left compared with that obtained in response to [Ca2+]o. In saponin (250 micrograms/mL)-treated skinned preparations, 3 mmol/L L-methionine also shifted the force-pCa curve to the left by 0.16 pCa units. This is the first demonstration that an essential amino acid directly acts on the myofilaments and modulates their responsiveness to Ca2+, thereby producing a positive inotropic effect.

Neurohumoral factors during transition from left ventricular hypertrophy to failure in Dahl salt-sensitive rats.

The relationship between the reduction in the positive inotropic effects (PIE) of beta-adrenergic stimulation and the level of systemic and tissue neurohumoral factors during the course from left ventricular (LV) hypertrophy to congestive heart failure (CHF) was studied in Dahl salt-sensitive rat (DS) CHF model. Control studies were performed in age-matched Dahl salt-resistant (DR) rats. In DS rats at CHF stage, plasma atrial natriuretic peptide (ANP) and norepinephrine (NE) levels were elevated markedly and myocardial NE level was decreased compared with those in the age-matched DR rats. On the other hand, at the hypertrophy stage, we observed no significant differences in plasma ANP or NE level between the two strains in spite of decrease in myocardial NE concentration. The PIE induced by isoproterenol was reduced at the stage of compensatory LV hypertrophy, which was followed by further reduction of PIE at CHF stage. The results distinctively indicate that beta-adrenergic desensitization in the myocardium which was accompanied with the abnormalities in local sympathoneuronal regulation begins during mechanically compensated LV hypertrophy and precedes systemic augmentation of sympathomimetic hormones.