Kinetics of Thallium-201 in Acute Phase of Myocardial Infarction: A Case Report.

BACKGROUND Thallium-201 has been widely used in clinical practice for the management of coronary heart disease, but little is known regarding its kinetics in the acute phase of myocardial infarction. CASE REPORT We report a 78-year-old man who developed acute inferior myocardial infarction during exercise thallium-201 scintigraphy. The patient underwent exercise testing with thallium-201 myocardial scintigraphy because of a single episode of chest pain. The workload was started with 25 watts and increased by 25 watts every 2 min on a bicycle ergometer with continuous monitoring of 12-lead electrocardiography. Thallium-201 was injected intravenously at 85% of the age-predicted maximal heart rate, and ST-segment elevations refractory to medication subsequently developed in the inferior leads, followed by chest pain. Scintigraphic image acquisition was deferred and he was transferred to the catheter laboratory in this hospital. Emergency coronary angiography showed occlusion in the right coronary artery, and stent implantation was successfully performed. The peak level of creatine kinase in the clinical course was 201 U/l. Scintigraphic images obtained 4 h after the onset of ST-segment elevation showed severely reduced activity in the left ventricular inferior wall, with partial redistribution 24 h later. Follow-up imaging performed 4 months later revealed increased accumulation of thallium-201 in the inferior wall. CONCLUSIONS Our case highlights the kinetics of thallium-201 during acute myocardial infarction.

Ventricular late potentials and myocardial fibrosis in hypertrophic cardiomyopathy.

AIMS: Ventricular late potentials (VLPs) represent delayed conduction due in part to myocardial fibrosis. We sought to examine the relationship of signal-averaged electrocardiography findings with myocardial fibrosis as assessed by cardiac magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM). METHODS: This study consisted of 41 HCM patients with sinus rhythm who had undergone risk assessment including CMR and signal-averaged electrocardiography such as VLPs, filtered QRS duration, low amplitude signal duration of the terminal filtered QRS below 40 µV (LAS), and root mean square voltage of the late 40 ms of the filtered QRS (RMS). The concordance rate between VLPs and myocardial fibrosis as assessed by CMR was examined. RESULTS: Late gadolinium enhancement (LGE) on CMR was detected in 13 patients, and VLPs were detected in 14. Filtered QRS duration, LAS, RMS, and VLPs were not associated with LGE. The results of LGE and VLPs were concordant in 26 patients, whereas 15 exhibited discordance. Patients with discordance had a higher maximum wall thickness (24.1 ±â€¯4.0 mm versus 21.0 ±â€¯5.9 mm, p < 0.05), higher LGE volume (2.3 ±â€¯1.2 g/cm versus 0.0 ±â€¯0.8 g/cm, p < 0.01), lower LGE volume/the total number of sites with LGE (1.5 ±â€¯0.7 versus 3.1 ±â€¯2.8, p < 0.01), and predominant LGE location of the interventricular septum and anterior wall (60% versus 8%, p < 0.01) than patients with concordance. CONCLUSION: VLPs were not a reliable marker for the detection of myocardial fibrosis as assessed by LGE on CMR in our cohort of patients with HCM. CONDENSED ABSTRACT: Ventricular late potentials on signal-averaged electrocardiography represent delayed conduction due in part to myocardial fibrosis but were not an alternative to cardiac magnetic resonance for detecting myocardial fibrosis in patients with hypertrophic cardiomyopathy.

A Case of Isolated Septal Myocardial Infarction: Myocardial Perfusion-metabolism Mismatch as a Tool for Diagnosis.

Isolated septal myocardial infarction is an uncommon condition with diagnostic difficulty due to small infarction size and anatomical variations. We report a case of isolated septal myocardial infarction, in which the diagnosis was confirmed not by electrocardiographic, echocardiographic, or angiographic findings, but by nuclear imaging. A 46-year-old man with chest discomfort exhibited ST-segment elevations in leads V1 and V2, and borderline abnormalities of the septal wall motion on echocardiography. Emergency coronary angiography demonstrated delayed flow in the second septal branch of the left anterior descending coronary artery. Intravascular ultrasound showed plaque in the proximal portion of the septal branch without evidence of plaque rupture. No balloon angioplasty or stent implantation was required because the flow delay in the septal branch disappeared after the intravascular ultrasound procedure. Myocardial perfusion-metabolism mismatch, as assessed by resting thallium-201 and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid, was seen in the mid-septal region.

Onset of new diastolic murmur as a sign of bioprosthetic valve dysfunction: A case report.

The diagnosis of prosthetic valve dysfunction remains challenging because visualization is limited due to artifacts on echocardiography. We herein report a case of bioprosthetic valve dysfunction, in which cardiac auscultation was useful as an initial clue to the diagnosis. An 81-year-old man, who had undergone bioprosthetic aortic valve replacement due to aortic stenosis 10 years earlier, presented to the emergency department with chest discomfort. Cardiac auscultation revealed a newly developed diastolic murmur, although no diastolic murmurs were previously detected on auscultation or phonocardiography. There were no notable changes in electrocardiography, chest radiograph, laboratory tests, or echocardiography except for trivial aortic regurgitation. His hemodynamic status progressively deteriorated due to prosthetic valve dysfunction, which was later confirmed on echocardiography, and aortic valve re-replacement was semi-urgently performed with success. The diastolic murmurs disappeared after surgery. .

The perfusion index is a useful screening tool for peripheral artery disease.

The number of people with peripheral artery disease (PAD) has been increasing globally; therefore, it is important to explore more options to screen patients who are at a risk of developing PAD. The perfusion index (PI) represents the degree of circulation through the peripheral tissues and is measured noninvasively. We investigated the correlation between the PI and ankle-brachial index (ABI) to explore whether the PI could be used a screening tool for PAD. This cross-sectional study included 390 patients. We measured the ABI and PI for all patients. The median ABI value was 1.06 (0.92-1.13); the PI was 1.7% (0.9-3.5). The PI was higher in men than in women (P < 0.0001). The PI was positively correlated with the estimated glomerular filtration rate and ABI in both men and women. The sensitivity and specificity of the PI to predict PAD (ABI ≤0.9) were 90.0% and 80.3%, respectively, and the cutoff PI value was 1.5% in men. The sensitivity and specificity of the PI to predict PAD were 82.1% and 79.2%, respectively, and the cutoff PI value was 1.1% in women. PI could be a reliable screening tool for diagnosing PAD because it does not restrict the patient's mobility, can be completed in a short time period, and is associated with reduced costs.

Electrocardiographic changes as a marker of improved subendocardial ischemia in a patient with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) patients sometimes develop subendocardial ischemia without coronary artery stenosis. We report a case of non-obstructive HCM, in which electrocardiographic changes were observed with improvement of subendocardial ischemia. A 76-year-old man presented with chest pain on exertion. The electrocardiogram revealed left ventricular (LV) hypertrophy with repolarization abnormalities. No coronary stenosis was found on computed tomography angiography, but thallium-201 exercise scintigraphy revealed transient LV cavity dilation after exercise, consistent with subendocardial ischemia. His chest symptoms disappeared after starting verapamil. Transient LV cavity dilation improved without a reduction in exercise tolerance, as did electrocardiographic abnormalities without any changes on echocardiography.

Murmur Associated with Diastolic Paradoxical Jet Flow in a 43-Year-Old Man with Hypertrophic Cardiomyopathy.

A diastolic paradoxical jet flow, often seen in patients with hypertrophic cardiomyopathy, is a unique flow from the apex toward the base of the left ventricle during isovolumic relaxation. To date, this phenomenon appears to have been noninvasively detected only on echocardiograms. We report the case of a 43-year-old man with hypertrophic cardiomyopathy and a diastolic paradoxical jet flow, in whom cardiac auscultation revealed a soft S4, a systolic ejection murmur, and a low-pitched early diastolic murmur immediately after S2 at the apex. On comparing his echocardiographic findings with those on phonocardiograms and apexcardiograms, we confirmed that the unusual murmur coincided with the diastolic jet flow. To our knowledge, this is the first case in which heart murmurs associated with a diastolic paradoxical jet flow have been clearly described. Because these flows can increase the risk of adverse outcomes, detecting any associated murmurs by methods other than echocardiography is worthwhile, even in the era of advanced imaging techniques.

Third and Fourth Heart Sounds and Myocardial Fibrosis in Hypertrophic Cardiomyopathy.

BACKGROUND: The 4th heart sound (S4) is commonly heard in patients with hypertrophic cardiomyopathy (HCM). The 3rd heart sound (S3) is also audible in HCM patients regardless of the presence or absence of heart failure. These extra heart sounds may be associated with myocardial fibrosis because myocardial fibrosis has been suggested to affect left ventricular compliance.Methods and Results:The present retrospective study evaluated 53 consecutive HCM patients with sinus rhythm who had no symptoms of heart failure and underwent an initial assessment including phonocardiography, echocardiography, and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). S3 was detected on phonocardiography in 13% of all patients, and S4 was recorded in 75% of patients. Patients with S3 had a higher incidence of LGE and larger LGE volumes (86% and 11.5±2.4 g/cm, respectively) than patients without S3 (33% and 2.5±0.8 g/cm, respectively; P=0.02 and P=0.002). The presence of S4 was not associated with MRI findings, including the incidence of LGE and LGE volume. The diagnostic value of S3 for the detection of LGE was highly specific (97%), with a low sensitivity (29%). CONCLUSIONS: Myocardial fibrosis, as assessed by LGE, was associated with S3 but not with S4 in patients with HCM. These results may contribute to the risk stratification of patients with HCM.

Rhabdomyolysis after High Intensity Resistance Training.

Rhabdomyolysis, which is a characteristic occurrence in associated with muscle cell necrosis, develops due to various causes. We herein report a rare case of a patient with rhabdomyolysis after high intensity resistance training, in which markedly elevated levels of serum creatine kinase (CK) and urine myoglobin were observed. A previously healthy 37-year-old man presented with severe myalgia and dark urine after performing high-intensity exercise. The patient's serum CK level was 95,100 U/L and his urine myoglobin level was 160,000 ng/mL. His symptoms and laboratory findings gradually improved with the intravenous administration of saline and no complications (including electrolyte imbalance and acute renal failure) developed.

Diastolic murmur in mid-ventricular obstructive hypertrophic cardiomyopathy: A case report.

A diastolic murmur is informative in the diagnosis of valvular heart disease, such as mitral stenosis and aortic regurgitation. Patients with hypertrophic cardiomyopathy (HCM) could have diastolic murmurs, although this is not widely recognized. We describe an illustrative case of HCM which was found to have a diastolic murmur associated with mid-left ventricular obstruction. An asymptomatic 65-year-old male was referred because of an abnormal electrocardiogram. Cardiac auscultation showed a soft fourth heart sound, a systolic ejection murmur, and a third heart sound followed by a diastolic murmur at the apex. On phonocardiography, the mid-diastolic murmur was predominantly low-pitched with an onset of about 200 ms after the second heart sound and a duration of approximately 150 ms. The timing of the diastolic murmur was consistent with an increased blood inflow during diastole in the mid-ventricular obstruction (2.0 m/s), which was produced by narrowing between the hypertrophied ventricular septum and the protrusion of the anterior papillary muscle. .

Unusual clinical course after surgical repair of unruptured aneurysm of sinus of Valsalva.

Aneurysms of the sinus of Valsalva are characterized by dilatation of at least one of the three aortic sinuses. We experienced a case with unruptured aneurysm of the right sinus of Valsalva, in which serial imaging studies were useful in assessing a rare complication after surgical repair. An asymptomatic 75-year-old man underwent patch closure of the aneurysm orifice because of progressive enlargement of the aneurysm. The postoperative course was uneventful, and computed tomography (CT), performed a week after the patch repair, showed no leakage of contrast medium into the isolated aneurysm. Three months later, echocardiography showed decreased size of the aneurysm with heterogeneous echogenicity and possible blood flow in the aneurysm, findings suggestive of thrombus formation and a recurrent fistula. CT with contrast medium showed partial recanalization between the patched aneurysm and the right sinus of Valsalva. Follow-up echocardiography, performed 1 year after surgery, revealed neither definite aneurysm nor shunt flow of Valsalva. The present case highlights that non-invasive follow-up can be an alternative option when carried out with caution in selected patients with incomplete closure of Valsalva aneurysm.

Notched QRS for the assessment of myocardial fibrosis in hypertrophic cardiomyopathy.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) sometimes develop myocardial fibrosis in association with adverse cardiovascular events. Electrocardiography (ECG) could provide helpful information on myocardial fibrosis in HCM, as in coronary artery disease. METHODS AND RESULTS: A total of 60 patients with HCM without bundle branch block underwent cardiac magnetic resonance imaging (CMR). The extent or location of late gadolinium enhancement (LGE) was examined in relation to 12-lead ECG. A notch on QRS was defined as at least 2 consecutive spikes in the same polarity with a reversal of direction ≥90° and the initial negative deflection ≥0.05 mV. LGE was associated with notched QRS, leftward QRS axis, and prolonged QRS duration, but not with any other findings such as abnormal Q waves, R-wave amplitude, or ST-T changes. Notched QRS was most useful in determining the presence or absence of myocardial fibrosis, with a sensitivity of 70% and a specificity of 81% using a cut-off of the number of leads with notched QRS ≥2. The number of notched QRS leads was positively correlated with LGE volume (P<0.01) and the lead distribution of notched QRS was informative about the location of LGE. CONCLUSIONS: A notch on QRS was useful in estimating myocardial fibrosis as assessed on CMR LGE in HCM patients without bundle branch block.

Additional heart sounds during early diastole in a patient with hypertrophic cardiomyopathy and atrioventricular block.

A third heart sound (S3) and a fourth heart sound (S4) are similarly perceived as low-pitched sounds and can be difficult to distinguish in some conditions, such as tachycardia or arrhythmia. We report a case with hypertrophic cardiomyopathy and Wenckebach second-degree atrioventricular block, in which the S4 was initially misdiagnosed as an S3 on auscultation and later confirmed using a phonocardiogram with an apexcardiogram. Interestingly, the amplitude of the S4 dynamically and regularly fluctuated in proportion to the interval between the S4 and the preceding ventricular contraction. These findings were associated with transmitral inflow patterns assessed by Doppler echocardiography, highlighting the importance of not only transmitral A but also E waves for the amplitude of S4 in patients with arrhythmias. .