Basal Septal Hypertrophy as the Early Imaging Biomarker for Adaptive Phase of Remodeling Prior to Heart Failure

Hypertension plays a dominant role in the development of left ventricular (LV) remodeling and heart failure, in addition to being the main risk factor for coronary artery disease. In this review, we focus on the focal geometric and functional tissue aspects of the LV septal base, since basal septal hypertrophy (BSH), as the early imaging biomarker of LV remodeling due to hypertensive heart disease, is detected in cross-sectional clinic studies. In addition, the validation of BSH by animal studies using third generation microimaging and relevant clinical observations are also discussed in the report. Finally, an evaluation of both human and animal quantitative imaging studies and the importance of combined cardiac imaging methods and stress-induction in the separation of adaptive and maladaptive phases of the LV remodeling are pointed out. As a result, BSH, as the early imaging biomarker and quantitative follow-up of functional analysis in hypertension, could possibly contribute to early treatment in a timely fashion in the prevention of hypertensive disease progression to heart failure. A variety of stress stimuli in etiopathogenesis and the difficulty of diagnosing pure hemodynamic overload mediated BSH lead to an absence of the certain prevalence of this particular finding in the population.

Hemodynamic stress and microscopic remodeling

BACKGROUD

Heart responds to physiologic and pathologic conditions and sympathetic drive plays an important role. It has been documented that LV base is more dominantly affected by sympathetic drive compared to the other regions. LV base is more dominantly exposed to wall stress in the initial period of remodeling due to pressure-overload, since LV cavity is the largest at base. Basal septal hypertrophy (BSH) in cross-sectional data is associated with the early phase of hypertensive heart disease. BSH was confirmed by 3rd generation microscopic ultrasound in small animals. BSH as the closest location to increased afterload could be detected in variety of stress stimuli and result in a huge septal hypertrophy in advance cases possibly related to earlier exposure of hemodynamic stress to septal wall.

CONCLUSION

Effective geometric and functional evaluation of initial remodeling due to hemodynamic stress is important according to both human and animal data. These findings possibly contribute to early recognition of adaptive phase of hypertensive remodeling and more effective management in a timely fashion.

Ultimate phases of hypertensive heart disease and stressed heart morphology by conventional and novel cardiac imaging

Early recognition of hypertensive heart disease is needed to prevent macrovascular and microvascular damage. Hypertension (HTN) is a risk factor for coronary artery disease, and plays a prominent role in the development of adverse left ventricular (LV) remodeling and heart failure. Here, we review new knowledge on effects of HTN on cardiac geometry and function, obtained from multimodality cardiac imaging, including echocardiography, positron emission tomography and magnetic resonance imaging. Early recognition of changes in LV geometry and function induced by HTN could identify patients at risk for end-organ damage, who could be targeted for close monitoring and intensive therapy. Basal septal hypertrophy as the early imaging biomarker at the adaptive phase may be a specific aspect not only in hypertensive heart but stress-related conditions and called stressed heart morphology.

Higher incidence of vasodilator-induced left ventricular cavity dilation by PET when compared to treadmill exercise-ECHO in hypertrophic cardiomyopathy

BACKGROUND

Vasodilator-induced transient left ventricular cavity dilation (LVCD) by positron emission tomography (PET) is associated with microvascular dysfunction in hypertrophic cardiomyopathy (HCM). Here we assessed whether HCM patients who develop LVCD by PET during vasodilator stress also develop LV cavity dilation by echocardiography (ECHO-LVCD) following exercise stress.

METHODS

A retrospective analysis of cardiac function and myocardial blood flow (MBF) was conducted in 108 HCM patients who underwent perfusion-PET and exercise-ECHO as part of their clinical evaluation. We performed a head-to-head comparison of LV volumes and ejection fraction (LVEF) at rest and stress (during vasodilator stress, post-exercise), in 108 HCM patients. A ratio > 1.13 of stress to rest LV volumes was used to define PET-LVCD, and a ratio > 1.17 of stress to rest LVESV was used to define ECHO-LVCD. Patients were divided into 2 groups based on the presence/absence of PET-LVCD. MBF and myocardial flow reserve were quantified by PET, and global longitudinal strain (GLS) was assessed by ECHO at rest/stress in the two groups.

RESULTS

PET-LVCD was observed in 51% (n = 55) of HCM patients, but only one patient had evidence of ECHO-LVCD (ratio = 1.36)-this patient also had evidence of PET-LVCD (ratio = 1.20). The PET-LVCD group had lower PET-LVEF during vasodilator stress, but ECHO-LVEF increased in both groups post-exercise. The PET-LVCD group demonstrated higher LV mass, worse GLS at rest/stress, and lower myocardial flow reserve. Incidence of ischemic ST-T changes was higher in the PET-LVCD group during vasodilator stress (42 vs 17%), but similar (30%) in the two groups during exercise.

CONCLUSION

PET-LVCD reflects greater degree of myopathy and microvascular dysfunction in HCM. Differences in the cardiac effects of exercise and vasodilators and timing of stress-image acquisition could underlie discordance in ischemic EKG changes and LVCD by ECHO and PET, in HCM.

Stress Myocardial Blood Flow Heterogeneity Is a Positron Emission Tomography Biomarker of Ventricular Arrhythmias in Patients With Hypertrophic Cardiomyopathy

Patients with hypertrophic cardiomyopathy (HC) are at increased risk of sudden cardiac death. Abnormalities in myocardial blood flow (MBF) detected by positron emission tomography (PET) are common in HC, but a PET marker that identifies patients at risk of sudden cardiac death is lacking. We hypothesized that disparities in regional myocardial perfusion detected by PET would identify patients with HC at risk of ventricular arrhythmias. To test this hypothesis, we quantified global and regional MBFs by ¹³NH₃-PET at rest and at stress, and developed a heterogeneity index to assess MBF heterogeneity in 133 symptomatic patients with HC. The MBF heterogeneity index was computed by dividing the highest by the lowest regional MBF value, at rest and after vasodilator stress, in each patient. High stress MBF heterogeneity was defined as an index of ≧1.85. Patients with HC were stratified by the presence or the absence of ventricular arrhythmias, defined as sustained ventricular tachycardia (VT) and/or nonsustained VT, during follow-up. We found that global and regional MBFs at rest and stress were similar in patients with HC with or without ventricular arrhythmias. Variability in regional stress MBF was observed in both groups, but the stress MBF heterogeneity index was significantly higher in patients with HC who developed ventricular arrhythmias (1.82 ± 0.77 vs 1.49 ± 0.25, p <0.001). A stress MBF heterogeneity index of ≧1.85 was an independent predictor of both sustained VT (hazard ratio 16.1, 95% confidence interval 3.2 to 80.3) and all-VT (sustained-VT + nonsustained VT: hazard ratio 3.7, 95% confidence interval 1.4 to 9.7). High heterogeneity of stress MBF, reflected by an MBF heterogeneity index of ≥1.85, is a PET biomarker for ventricular arrhythmias in symptomatic patients with HC.

Effect of Diffuse Subendocardial Hypoperfusion on Left Ventricular Cavity Size by 13N-Ammonia Perfusion PET in Patients With Hypertrophic Cardiomyopathy

Vasodilator-induced transient left ventricular (LV) cavity dilation by positron emission tomography (PET) is common in patients with hypertrophic cardiomyopathy (HC). Because most patients with PET-LV cavity dilation lack obstructive epicardial coronary artery disease, we hypothesized that vasodilator-induced subendocardial hypoperfusion resulting from microvascular dysfunction underlies this result. To test this hypothesis, we quantified myocardial blood flow (MBF) (subepicardial, subendocardial, and global MBF) and left ventricular ejection fraction (LVEF) in 104 patients with HC without significant coronary artery disease, using ¹³NH₃-PET. Patients with HC were divided into 2 groups, based on the presence/absence of LV cavity dilation (LVvolume_stress/LVvolume_rest >1.13). Transient PET-LV cavity dilation was evident in 52% of patients with HC. LV mass, stress left ventricular outflow tract gradient, mitral E/E', late gadolinium enhancement, and prevalence of ischemic ST-T changes after vasodilator were significantly higher in patients with HC with LV cavity dilation. Baseline LVEF was similar in the 2 groups, but LV cavity dilation⁺ patients had lower stress-LVEF (43 ± 11 vs 53 ± 10; p <0.001), lower stress-MBF in the subendocardial region (1.6 ± 0.7 vs 2.3 ± 1.0 ml/min/g; p <0.001), and greater regional perfusion abnormalities (summed difference score: 7.0 ± 6.1 vs 3.9 ± 4.3; p = 0.004). The transmural perfusion gradient, an indicator of subendocardial perfusion, was similar at rest in the 2 groups. Notably, LV cavity dilation⁺ patients had lower stress-transmural perfusion gradients (0.85 ± 0.22, LV cavity dilation⁺ vs 1.09 ± 0.39, LV cavity dilation^-; p <0.001), indicating vasodilator-induced subendocardial hypoperfusion. The stress-transmural perfusion gradient, global myocardial flow reserve, and stress-LVEF were associated with LV cavity dilation. In conclusion, diffuse subendocardial hypoperfusion and myocardial ischemia resulting from microvascular dysfunction contribute to development of transient LV cavity dilation in HC.

Fuzzy Expert System Approach for Determination of α-Linolenic Acid Content of Eggs Obtained from Hens by Dietary Flaxseed

This paper presents the development of a fuzzy expert system (FES) for determination of α-linolenic acid content of eggs, obtained from hens fed dietary flaxseed. Based on experimental values FES models were designed using MATLAB 6.5 fuzzy logic toolbox in Windows XP running on Intel 1.9 Gh environment. It was used time and flaxseed ratio as input parameters and linolenic acid content as output. There was a good correlation ( R2 = 0.9983) between experimental values and FES (P < 0.05, t-test).

Contractility evaluation by 2 dimensional echocardiography and gated SPECT myocardial perfusion scintigraphy in hypertensive patients with clinical presentation of atypical chest pain

BACKGROUND

Hypertension (HT) is a growing health problem in the population and associated with increased cardiovascular event risk and mortality. In hypertensive patients, progressive left ventricular (LV) contractility deterioration is detectable by gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy9. We planned this study to explore the agreement in ejection fraction (EF) determination between 2 dimensional echocardiography and gated SPECT analysis in selected group of patients with hypertension.

PATIENTS AND METHODS

We studied 26 consecutive patients (mean age 56.5 ± 8.8 years; 6 men) with hypertension. Quantitative contractility analysis by both echocardiography and SPECT at rest was performed to investigate the agreement between two diagnostic tests.

RESULTS

EF at rest was greater than 55 % in all patients. All patients had a clinical presentation of atypical chest pain. Therefore, in addition to quantitative contractility analysis at rest by echocardiography and myocardial SPECT perfusion scintigraphy, we examined ischemia by stress induction and determined that 10 patients had ischemic finding (38.4 %). The mean value of EF calculated by echocardiography was 67.5 ± 5.7 %, while EF by gated SPECT was 72.8 ± 8.5 %. We documented an acceptable agreement in EF determination between these 2 diagnostic tests by meaningful correlation (r = 0.556, p = 0.003). There was no regional contractility deterioration despite existence of ischemia in 10 patients of the study group.

CONCLUSIONS

We observed that both echocardiography and gated SPECT can be used for quantification of EF in the hypertensive patients with an acceptable agreement.

Stress-induced regional features of left ventricle is related to pathogenesis of clinical conditions with both acute and chronic stress

Tako-tsubo cardiomyopathy is a relatively newly described acute and reversible left ventricular (LV) dysfunction triggered by emotional stress. The disease is associated with excessive sympathetic stimulation, microvascular dysfunction and abnormal myocardial tissue metabolism. Recently, we have pointed out that tako-tsubo cardiomyopathy may be associated with particular LV features which are also described by quantitative echocardiographic methods in hypertensive heart disease. The patients with acute or chronic stress can be presented clinically by stress-induced LV hypercontractility of LV base, relevant LV outflow tract obstruction and narrowed cavity. Recent observations also have confirmed the possibility of association of both acute and chronic conditions in a clinical presentation of the patients. Therefore, we believe that the presence of both resistance and hypercontractile response of LV base to stress induction compared with midapical region in clinical conditions with acute or chronic stress is important in the disease process.

Single photon emission computed tomography: an alternative imaging modality in left ventricular evaluation

Various diagnostic imaging modalities have been used for quantitative left ventricular (LV) parameters. Because of the suboptimal value of the most widely used technology, two-dimensional (2D) echocardiography, 3D ultrasonographic imaging has improved accuracy for LV volume and function. Single photon emission computed tomography (SPECT) is another diagnostic method where LV volumetric and functional parameters can be accurately provided by gated myocardial perfusion tomographic slices. First pass radionuclide venticulography is another imaging modality which has some practical limitations. Despite lower ejection fraction (EF) values compared with invasive approach, noninvasive techniques are accurate in determination of normal and depressed EF. Noninvasive techniques with 3D approach including gated SPECT are beneficial for not only global but also regional LV evaluation. It has been mentioned that the slight difference between echocardiography and SPECT could be caused by the diverse population studied. The results of diagnostic stress tests support that SPECT is feasible to use in evaluation of LV volume and functional analysis. Magnetic resonance imaging is an expensive modality to use routinely, but it preserves its importance in selected patients for providing precise LV geometric data.

Acceleration of hepatobiliary dynamics in liver transplant donors

This study compared hepatobiliary scintigraphy findings in livers before and after liver graft donation to examine whether there is a change in hepatobiliary dynamics. Nine donors underwent hepatobiliary scintigraphy with intravenous injection of Tc-99m mebrofenin 1 day before and during the first week after left liver lobectomy. Five donors also underwent additional scintigraphy more than 1 year postsurgery. Images were acquired every second for the first minute, and then every minute for the next 40 minutes. Hepatic arterial perfusion index and portal perfusion index(PPI) were calculated from the images acquired during the first minute. For the function phase the computed parameters included: hepatic extraction efficiency, (HEE), time to appearance of activity in the intrahepatic biliary channels, and in the intestine, time to half maximal activity, and activity retained in the liver parenchyma at 40 minutes. Time to appearance of intrahepatic biliary channels and of intestinal activity was shorter among scintigraphies obtained within 1 week postsurgery compared to the preoperative values. Early after the operation HEE increased and PPI decreased significantly. Visual inspection of the scintigraphy scan obtained in all donors, within the first week postsurgery revealed hypertrophy of the right liver lobe. None of the patients showed progression of right lobe activity to the left side, even among scans obtained more than 1 year after donation. Reduced time to activity in the biliary channels and intestine and increased HEE suggest acceleration of hepatobiliary dynamics.

Macroanatomic investigations of the blood supply of thoracic limb of Kangal dogs

In this study, the arterial supply of the thoracic limb was investigated in Kangal dogs. Twelve adult healthy Kangal dogs of either sex were used. Latex was injected into the common carotid artery, and then the axillary artery was dissected. The axillary artery is a continuation of the subclavian artery and supplies the thoracic limb in Kangal dogs. The axillary artery gave off a deltoid branch and external thoracic, lateral thoracic, and subscapular thoracic arteries in its course along the thoracic wall. The axillary artery continues distally as the brachial artery in the arm. The brachial artery gives rise to the cranial humeral circumflex, deep brachial, bicipital, ulnar collateral, superficial brachial, transverse cubital, and common interosseus arteries. It continues as the median artery after giving off the common interosseus artery. It was observed that the deep antebrachial artery arose from the median artery at the proximal third of the forearm. In the distal third of the forearm, the median artery divided into the palmar carpal and dorsal carpal branches. The deep palmar branch of the radial artery and deep branch of the palmar branch of the caudal interosseus artery form the deep palmar arch. The median artery joined the superficial branch of the palmar branch of the caudal interosseus artery to constitute the superficial palmar arch. The radial artery and cranial interosseus artery contributed to the dorsal carpal rete. The ulnar artery contributed to the formation of the deep and superficial palmar arches.

Reproductive outcome after metroplasty

OBJECTIVE

To evaluate the impact of abdominal metroplasty for symmetric uterine anomalies on reproductive performance.

METHOD

A retrospective analysis of 24 patients who conceived following metroplasty for symmetric congenital anomalies during a 5-year period.

RESULTS

In patients with poor obstetric histories before surgery, the overall fetal survival rate increased from 2.5%, before treatment to 73.3% after treatment and 90.5% of women gave birth to a surviving infant. The remaining three patients suffering from infertility delivered a full-term infant after metroplasty. Antenatal complications occurred in 56.7% of the pregnancies.

CONCLUSION

Abdominal metroplasty clearly improves fetal survival particularly in women suffering from a history of poor obstetric outcome associated with symmetric malformations.

Causative factors in first trimester abortion failure

OBJECTIVE

To evaluate the main contributors to failed first trimester abortions.

PATIENTS AND DESIGN

Forty-two cases of unintentional continued pregnancy were detected among 23,000 termination procedures performed between 1989 and 1995. The patients were diagnosed either at follow-up visits or at the time of operation due to abnormal pelvic findings or discrepancy between the expected and obtained tissue.

RESULTS

The failure rate was found to be 0.18%. Among the patients with failed abortion 8 patients had unsuspected anomalies; two of these patients conceived with an intrauterine device in position; 7 patients had uterine malposition (2 markedly anteverted and 5 markedly retroverted), and 2 patients had leiomyomas. No genital disorder was identified in the remaining 25 women. Among these 25 women, 10 had gestations beyond 8 weeks, for which suction curettage followed by sharp curettage was performed. Among the remaining 15 in whom only suction curettage was used for termination, 13 had less than 6 weeks of gestation at the time of pregnancy termination.

CONCLUSION

When a termination fails, when scanty tissue is obtained, or when doubt exists about the termination, an extrauterine pregnancy must be ruled out and other causes of termination failure should be considered such as technical failure, uterine anomaly, or malposition.

Treatment of Bartholin's cyst and abscess: excision versus silver nitrate insertion

In a prospective randomized study, intracavitary silver nitrate (AgNO3) stick insertion (n = 25) was compared to the conventional excision technique (n = 25) for Bartholin's cyst or abscess. Two groups were similar with regard to age, previous Bartholin's cyst/abscess and size of the cyst. Operation and healing time was significantly shorter in the AgNO3 group (P < 0.001, P < 0.001, respectively). Chemical burning in the vulva was observed in one patient in the AgNO3 group, whereas hematoma on the operation site occurred in two patients in the excision group. Scar formation was found in two patients in whom excision was performed. Patients were followed for a period of 2 years and recurrence was not found in any of the cases in both groups. We conclude that, AgNO3 insertion treatment for Bartholin's cyst and abscess is as effective as excision and is associated with fewer complications. Because it is simple and inexpensive, it is an attractive alternative treatment modality for this common gynecological disease.

Rupture of the uterus

OBJECTIVES

To investigate the frequency of ruptured uterus, possible etiologic factors and fetomaternal outcomes.

METHODS

The birth records of 58262 deliveries at Dr Zekai Tahir Burak Women's Hospital from 1 January 1990 to 31 December 1992 were reviewed and the results compared with those of two previous studies reported from this hospital on the same subject.

RESULTS

Forty uterine ruptures occurred between 1990 and 1992, with a frequency of 0.068% (1/1457). All occurred spontaneously but 10 (25%) had no previous surgery, whereas 30 followed previous cesarean section. There was no traumatic uterine rupture during this period. Fetal mortality was 32.5% and no maternal deaths were recorded.

CONCLUSION

The rate of ruptured uterus has declined among our hospital population as etiologic factors responsible for the complication have been reduced.